Sexual Revolution: Defend It, If You Can

This is a brilliant article, which argues from good old-fashioned ethics that the sexual revolution has been and continues to be a Bad Thing. Here's his conclusion - I'd love to see an attempt at a response from someone who disagrees...

In other words, let the sexual revolution be justified on grounds of the common good. I believe it fails that test miserably, with evidence that is weighty, obvious, manifold, logically and anthropologically deducible, and clearly predictable by wisdom both pagan and Christian. Let them make their case, rather than asserting a principle that, in reality, would destroy the very idea of the common good. For if we cannot appeal to the common good in a matter so fundamental, I do not see how we can appeal to it in any other.

It's worth adding that I know we are now living after the sexual revolution, and there's no point trying to pretend otherwise.

Sex and the Pope

There's a really interesting article by Peter Hitchens here about people's response to the Pope's visit. It's well worth a read - here's the section that struck me most...

The special condemnation reserved for the Romish church also suggests, absurdly, that such horrors never took place, or were covered up by, liberal secular institutions. They did, and have been. Yet this is never advanced as an argument against the secular liberal state (and it would be a bad argument, if it were).

The sex scandal is not, as it happens, the real reason for the anger directed against the Bishop of Rome. If it were, then the undoubted case against the Roman Catholic hierarchy could be made without all the puce-faced exaggerations, straightforward lies and total lack of proportion which infect it. It is overblown precisely because it is not the true issue, but a pretext.

This is what it is really about: the sons and daughters of the sexual revolution, the inheritors of 1968, are actively infuriated by anyone who dares to suggest that their behaviour in their personal lives might be, or might ever have been, selfish and absolutely wrong

Steve Jobs, Apple, Porn and Freedom

I'm not normally a great fan of Apple. I think their products are over-hyped, over-priced and too hard to tinker with. I think in some sections of society (and that includes a fair few friends of mine from theological college), they've reached the status of a pseudo-religion. I remember one of my best friends had an apple laptop. It fell off the sofa and stopped working, necessitating a long drive to the nearest Apple franchise shop then cost a lot to repair. My PC cost half as much, as the same sort of performance, is a lot harder to break and a lot easier to fix.

But then this comes along. I've deliberately linked to Albert Mohler rather than the original story because I think his analysis of this is good. I've got to say, I agree with Steve Jobs on this. Freedom from is often far more important than freedom to.

Of course, I think that freedom is actually meaningless unless we specify "freedom from something" or "freedom to something". We are never free to do whatever we want - we can't fly to the moon unaided, for example. And as a Christian, I think the freedom that really matters is freedom to follow God, a freedom which only comes through slavery to Christ. But that's a different story...

Bits and Bobs - Drugs and Spiritual Experience, Contraceptives

There's some interesting research here about the ways in which some drugs can give people emotional experiences similar to those experienced in worship.

From the point of view of experience, it seems it's impossible to tell the difference between drug-induced and "natural" mystical experiences. Both are powerful. Both enable people to enjoy a transcendent moment. Both seem capable of transforming people so that they feel a greater sense of empathy for and unity with other people—what most people would call love.

That doesn't surprise me at all, because we're made as single entities - we don't have a separate bit of us labelled "soul", so you'd expect that any feeling that can be experienced as a result of something genuine can also be created by drugs or by other forms of artificial stimulation. And though experiences are important and useful, at the end of the day, the key question is one of truth and reality. Is the God we experience real and true? That's why discernment is important.

Meanwhile, Albert Mohler poses some interesting questions about the effect of the contraceptive pill on society. Personally, I suspect things would have turned out much better if its use had been restricted to married (or just about to be married) women.

John Piper argues that the cross has a benefit for unbelievers as well, in this case because it secures common grace and gives them time to repent.

A Christian psychotherapist discusses the problems caused to society by pornography.

Seven Habits of Highly Effective Christians is good for thinking about some of the qualities that help us tell others about Jesus.

Sermon on Identity

Here's a talk I gave the other week about our identity in Christ...

Or download it from here.

Wright - Lectionaries

Whenever you see, in an official lectionary, the command to omit two or three verses, you can normally be sure that they contain words of judgment. Unless, of course, they are about sex.
Tom Wright, Surprised by Hope, p.190

Divorce Lawyers

In private, divorce lawyers not only say you shouldn't employ yourself for your divorce; they also say you shouldn't employ them either - ie just don't get divorced.

The divorce rate among divorce lawyers is incredibly low - however much they dislike their husbands or wives, lawyers know it's not worth paying people like them a fortune to make things worse.

from here

Reminds me of the magnificently tragic film The War of the Roses, which features a divorce lawyer who always advises people to get reconciled to their partner because he has seen just how awful not being reconciled can be.

Transformation by the Renewing of the Mind

Too many reviews lately. Time for some meat. And, at the risk of generalising from my own experience, here it is...

Therefore, I urge you, brothers, in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God—this is your spiritual act of worship. Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is — his good, pleasing and perfect will.
Romans 12:1-2, NIV

For Paul, the normal way of seeing transformation in people's lives and the way that they act is by the renewal of their minds. That is part of the reason he so often spends the first half of his letters doing what can seem like dry theology - because he knew that simply telling people to do something doesn't make much difference. People need to be motivated to change, and that motivation often seems to come from having their mind changed first, so that they hear a dissonance between the way that they live and the way that they know it is better to live. Our actions flow from our thoughts, so transformation starts with the renewing of the mind.

I usually act in what I perceive to be my own best interests. Pretty much everyone does. So for me, when I do not do what I want to do, it is because I am in two minds about something. There is part of me that thinks that work is good; there is part of me that isn't actually convinced there's any point to it, so I don't do it. And that's part of the normal human experience, at least for the Christian - the sinful nature and the Spirit want different things, and both are in us. And part of that battle is the battle for the mind. It is teaching my mind to follow the Spirit, not the sinful nature, and doing so by meditating on the underlying truths.

In context, the example Paul is using is the idea of pride. Paul's letter so far has essentially been about how God has saved us by his grace, through faith, in Christ. And his first application in 12v3 is the consequence that we should not think of ourselves more highly than we ought to. If we want to deal with pride, we should spend time thinking about God's salvation by grace and praying through God's salvation by grace.

The same is true, only even more so, where we sin persistently and seemingly unavoidably in one area. When I do that, it is usually because the whole way that I think in that area is determined more by the world and the sinful nature than by God, his Word and his Spirit. And what we need to do in those situations is to identify the topic, to work round it in our own mind, rather as a gardener might do with the root of some horrible weed, and then pull it out, or cut it out, and replace it with how God views the topic.

Three quick examples - money, sex and power. There's lots more that could be written on each of them, and lots more that has been.

Money

The world's view is often that money makes people happier or is a good in itself. God's is that money passes away - just look at how often money and death are paired in the Gospels - and that while money can be useful, especially if given away, loving it is a root of all kinds of evil.

Sex

The world's view is often that sex is good and enjoyable and should be had as often as possible. God's view is that sex is a wonderful gift, and is a beautiful thing to be celebrated when it happens inside marriage, but outside is horrible and disgraceful. In my experience, Christians often tend to try to take the world's view, then bolt on the idea that sex outside marriage is wrong, which leads to an internally contradictory view and all kinds of tensions and problems.

Power

The world's view is often that power is a good and useful thing to have, and is used to serve the powerful. Hence if you are powerless, you should seek to take power. The Bible's view is that power should either be laid down or used to serve the powerless, and that if we are powerless, we should submit to those in power.

Therefore, I urge you, brothers, in view of God's mercy, to offer your bodies as living sacrifices, holy and pleasing to God—this is your spiritual act of worship. Do not conform any longer to the pattern of this world, but be transformed by the renewing of your mind. Then you will be able to test and approve what God's will is — his good, pleasing and perfect will.
Romans 12:1-2, NIV

David, Bathsheba and moral compromise in the Church

The story of David and Bathsheba from 2 Samuel 11 is fairly well known. Roughly speaking, David, military hero, awesome king of Israel and God's chosen and anointed leader takes a year off while his army is out fighting. He sees a woman - Bathsheba, who appropriately (or not) enough is taking a bath. David likes the look of her, has sex with her, she gets pregnant. Her husband, who isn't even an Israelite, is off fighting for David. David gets him back and tries to get him to sleep with his wife; he refuses as he's still mid-campaign, so David arranges for the tactics to go a little wonky to get Uriah killed.

The application of that story I hear second most often is that it's a bad idea to find yourself with lots of time on your hands and nothing to do, especially if you're a bloke with a fairly strong sex drive and opportunity to use it. That is a true and valid application. It's why 2 Samuel 11 comes right after 2 Samuel 10, which is about the war that David should have been fighting in instead of watching naked women. But I don't think it's the main point.

The application that I hear most often is that even the best human leaders mess up, but that doesn't stop God using them. That's kind of true, and it is definitely important to know and understand that there is such a thing as real forgiveness, but it is a) so not the point of the passage and b) like a surgeon, very dangerous when not qualified properly.

What is the main point? Well, in 2 Samuel 12, Nathan the prophet confronts David with his behaviour in quite a clever way, ending with this conclusion from God...

Why did you despise the word of the LORD by doing what is evil in his eyes? You struck down Uriah the Hittite with the sword and took his wife to be your own. You killed him with the sword of the Ammonites. Now, therefore, the sword will never depart from your house, because you despised me and took the wife of Uriah the Hittite to be your own.'

"This is what the LORD says: 'Out of your own household I am going to bring calamity upon you. Before your very eyes I will take your wives and give them to one who is close to you, and he will lie with your wives in broad daylight. You did it in secret, but I will do this thing in broad daylight before all Israel.' "

Then David said to Nathan, "I have sinned against the LORD."
Nathan replied, "The LORD has taken away your sin. You are not going to die. But because by doing this you have made the enemies of the LORD show utter contempt, the son born to you will die."

2 Samuel 12:9-14, NIV

Yes, David repents, and that's what Psalm 51 is about, and there's a lot we can learn about repentance from that. Repentance saves David's life here, but it doesn't make it all alright. The next EIGHT CHAPTERS are all about the virtual collapse of the kingdom because of David's sons Absalom and Amnon and their lack of self control when it comes to having sex with the wrong women and killing people, which was exactly David's problem. Later, David's son and successor Solomon would have the same problem with women, which would lead to the kingdom splitting up. The start of the disastrous downward spiral in Israel's history from the high point of God's promise to David in 2 Samuel 7 and his victories in 2 Samuel 8-10 is often traced to Solomon's palace building, or to his very large number of foreign wives who introduced adultery, but actually I think it starts with David and Bathsheba. Yes, there's a kind of repeat of that with Solomon, but Solomon is just following in the footsteps of his father, only worse, as Solomon's son does after him.

The key message of 2 Samuel 11, David and Bathsheba, is that sin among the leaders of God's people is incredibly destructive. Yes, it can be forgiven if and when we repent, but that only means we don't go to hell immediately (and sinning more because we think we can be forgiven needs to be repented of itself). But it doesn't take away the awful temporal consequences of that sin for God's people.

Not many of you should presume to be teachers, my brothers, because you know that we who teach will be judged more strictly. We all stumble in many ways. If anyone is never at fault in what he says, he is a perfect man, able to keep his whole body in check.
James 3:1-2, NIV

David was one of the best kings there was, but he was not good enough.

The lesson of this is that leaders need to be holy. And while that should be strived for, at the end of the day, it is unattainable. The only adequate leader of God's people, the only king who is good enough is Great David's Greater Son - Jesus.

Homosexuality

Hmmm.... No time to write much on this, though there is a huge amount to say, but was talking about it again last night, in the context of discussing homophobia and stuff and so thought it would be a good idea to record some controversial thoughts on it.

• No-one goes to hell for being gay.

• Homophobia (especially a fear of being thought to be gay) is deeply ingrained in large parts of British culture and in large parts of the church
• To treat homosexual sex outside marriage differently from hetereosexual sex outside marriage seems to be an example of homophobia.

• Sexual "orientation" is both continuous and fluid, though to varying degrees in different people.
• To define one's identity by sexual orientation (whether straight, gay, bisexual, 3 on the Kinsey scale, whatever) is unhelpful and flawed. We do not link our preference for sweet or sour foods to our identity - why should we link our preference for sex with men or sex with women?
• In light of the previous two aphorisms, the concept of orientation itself is in some ways deeply flawed and certainly unhelpful in debate.

• The Biblical doctrine of sex is intrinsically linked to the Biblical doctrine of marriage. To understand what the Bible teaches on the issue in the light of the new covenant, we need to approach the issue through the doctrine of marriage rather than by arguing over which OT laws do or don't apply
• A clear distinction needs to be drawn between temptation and sin. Temptation is fine. Jesus was tempted, quite possibly in homosexual ways (e.g. Hebrews 4:15). Sin is not fine.
• The primary Biblical mandate for how Christians are to act is to love rather than to judge.
• I see no reason why non-Christians should accept arguments based on "the Bible says..."

• In the light of that, it seems to me that Biblically, marriage is meant to be heterosexual and lifelong, and that sex belongs inside marriage and not elsewhere.
• If there are three men talking, then one of them goes away and has sexual fantasies about a woman, another goes away and has sex with a man, and the third goes away and is proud that he has controlled his sex life, Jesus would be most likely to condemn the third one. And the first and second are pretty much morally equivalent if we take Matthew 5:27 seriously.

Is Pornography Good?

Nothing I write here should be taken as in any way condoning lust. Lust (by which I mean something along the lines of "dwelling on the idea of having sexual intimacy with someone you're not married to") is wrong, but I don't expect non-Christians to agree with me on that at all, and discussing why lust is wrong is probably the subject for another time.

There's a common line among some people (and I used to be one of them) that men lusting is partly the fault of women for showing so much flesh. Sheikh Taj el-Din al-Hilali went much much much too far down that road, and Scott Adams lampooned him brilliantly for it. Yeah, I know it's a bit old news. I've been wanting to write this for over a month.

Al-Hilali was obviously wrong. Women wearing revealing clothing might not be the most loving thing to do if there are men around who have problems with lust (and most men do), but it doesn't force them to lust and it doesn't make them rape you. That's their fault. But if he was wrong, if it's actually mens choice whether they lust or not, if women wearing revealing clothing isn't intrinsically wrong, why is pornography wrong?

Here's another angle, which sheds some useful light on the situation. Paul wrote:

everything God created is good, and nothing is to be rejected if it is received with thanksgiving
1 Timothy 4:4, NIV

God created naked women (Genesis 2:22,25). So if everything God created is good, surely that means that the naked female form is good and is not to be rejected. So why is pornography wrong?

The answer, and one solution to lust, is in the verse. Everything God created is good, and nothing is to be rejected if it is received with thanksgiving.

I used to struggle a lot with lust. I still do, but a lot less than I used to. One of the ways I used to try and deal with lust was avoiding pictures of women wearing revealing clothes or no clothes at all. That's a fairly common approach among Christian men. There were loads of problems with that. I've got a very good memory and (at times) an overactive imagination. I can avoid actual images in my own space, but I can't avoid them in public space, and I can't avoid women wearing revealing clothes without cutting myself off from the world. So just trying to cut off the supply of images actually had very little effect.

So what about thanking God for them? After all, God made naked women. I find that if I see an attractive woman wearing suggestive clothing, and I thank God for making attractive women, it gets my whole attitude much more right, and I am much less likely to want to treat the women in ways that the God who made them would disapprove of. It also makes my attitude to women much healthier.

Here's another slant on it. In Romans 1, Paul has all kinds of sin stemming from just two - ingratitude and failing to worship God.

The wrath of God is being revealed from heaven against all the godlessness and wickedness of men who suppress the truth by their wickedness, since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God's invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse.

For although they knew God, they neither glorified him as God nor gave thanks to him, but their thinking became futile and their foolish hearts were darkened....

Romans 1:18-21, NIV

Paul then goes on to list loads of consequences and ways that the sin works itself out in people's lives. But if the essence of sin is ingratitude and failing to thank God, then isn't the essence of lust failing to thank God for attractive people and so want to experience them in the way that God designed? So how better to combat that than by thanking God for people instead of lusting after them?

So, my view is that pornography isn't wrong in itself. But if someone wants to look at pornography (of the sex they're attracted to), there's at least a 99% probability that their motivations are lustful and therefore wrong.

Oh yes, and a quick random plug for XXXChurch.com - #1 Christian Porn Site, if only because of the name.

the demystification of the person

From time to time, I come across the idea of demystification. As far as I can tell, it means that there's something everyone thinks is special, and someone explains why it's just ordinary. There's some areas (some conincidences, especially the kind that lie behind conspiracy theories) where I quite like doing it myself.

And then I come across it applied to normal people, and I really don't like it.

Here's the first big example I can remember getting annoyed about:

I was at teacher training college, and due to the government's cunning device to reduce the number of Physics teachers, I was having to teach biology (and specifically sex ed). The head of biology at the school, who was supervising me, told me that the school policy was to teach just the mechanics of what went on, without reference to relationships.

The text book, likewise, only referred to the mechanics of what was going on, though it called the process "making love" instead of "sexual intercourse", which was odd. To my mind, "sexual intercourse" is the closest polite term to meaning a purely physical act without necessarily reproductive consequences. But "making love" implies the context of love, which was not otherwise mentioned. Were they saying that this is all that "love" is?

My problem with the sex ed lessons was that, in removing the relational context from sex, they were implying that it was a merely physical act. They were taking something special, and making it seem normal.

Another example comes in what some medical schools teach about abortion. A not-yet-Christian "pro-choice" medical student told me that they are taught that the fetus is essentially a parasite on the mother's body - it depends totally on the mother for all its sustenance, potentially damaging the mother in doing so.

How is that different from a newborn baby, a disabled child, a seriously ill relative?

Yes, the dependancy relationships might be one way, but people consist of more than just their dependancy relationships. A fetus might be a bundle of cells that draws support from the mother at cost to the mother, but that does not mean that is all it is. Again, they are taking something special, and making it ordinary.

In many respects I agree with them. As far as souls and stuff are concerned, I'm a materialist. I think that I am a complex collection of atoms obeying the laws of Physics. But that is not the only level on which a description is possible. I can relate to other such complex collections of atoms obeying the laws of Physics. And while it might well be possible to reduce my interactions with them to the merely physical, to do so makes the description poorer.

On a physical level, I could say that many of the interactions between such complex collections of atoms are at a very high level of complexity, and to reduce them to simple mechanics is to simplify them too much.

In the same way, to reduce a film to a large number of photons passing through a complex coloured filter and scattering off a screen is a valid description, but in reducing the descrption to that level, it impoverishes it by missing off the detail of complex interactions that is the real point.

I could go further. I might be a complex collection of atoms obeying the laws of Physics, but by his awesome grace, I can interact at a complex level with the God who made the laws of Physics. Yes, it might be possible to describe that in terms of what the ions and molecules in my brain are doing, but such a description would completely miss the awesome glory of God.

Union with Christ

Introduction

A couple of things recently have been prompting me to write something about what it means for us to be united with Christ. For my part, I think it is one of the key doctrines of the New Testament – I'd say an understanding of union with Christ is essential to an understanding of justification; it's fundamental. It also seems to be a poorly understood doctrine. That's not to say I do fully understand it; I don't, of course I don't. But I think that, by God's grace, I am starting to have a faint idea of some of what it means. So I'll try and write about that. I'm writing for Christians, but others are free to read it.

What Does "Union with Christ" Mean?

The best place to start is probably Romans 6:1-13

What shall we say then? Are we to continue in sin that grace may abound? By no means! How can we who died to sin still live in it? Do you not know that all of us who have been baptised into Christ Jesus were baptised into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.

For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin. For one who has died has been set free from sin. Now if we have died with Christ, we believe that we will also live with him. We know that Christ being raised from the dead will never die again; death no longer has dominion over him. For the death he died he died to sin, once for all, but the life he lives he lives to God. So you also must consider yourselves dead to sin and alive to God in Christ Jesus.

Let not sin therefore reign in your mortal bodies, to make you obey their passions. Do not present your members to sin as instruments for unrighteousness, but present yourselves to God as those who have been brought from death to life, and your members to God as instruments for righteousness.
Romans 6:1-13, ESV

What, according to Paul does it mean for us to be “baptised into Christ” and into his death?

Paul says that our baptism into Christ means that we somehow share in Christ's death – we are crucified with him (v6), we died with him (v5) and are buried with him (v4). Therefore we have been raised in him (v13) and live in him (v11).

Note that Paul doesn't write here that Christ was crucified for us and therefore that we should give our lives for him. Nor does he say that we are compelled not to sin because of what Jesus has done for us, which is what I imagine many of us would say in answer to the question of verse 1. Paul writes that we have been united with Christ in his death and in his resurrection – that because he has died, we have died and because he has been raised, we have been raised, therefore we should be living like it. Christ is not just the pattern for us to follow; he is the template in which we live.

Paul uses the same idea in Colossians 2:20

If with Christ you died to the elemental spirits of the world, why, as if you were still alive in the world, do you submit to regulations...?
Colossians 2:20, ESV

"In Christ"

We see the same idea especially in Paul's use of the phrase “in Christ”. I used to think that it was just a throwaway phrase Paul used because it sounded nice, but it isn't; it's fundamental to what Paul is saying and in my opinion is the key to most of Paul's theology.

Paul uses “in Christ” as a way of referring to Christians (e.g. Romans 16:7), but far more often in connection with the blessings we have received. For example:

“the redemption that is in Christ Jesus”
Romans 3:24

“no condemnation for those who are in Christ Jesus”
Romans 8:1

“If anyone is in Christ, he is a new creation”
2 Corinthians 5:17

“In him we have redemption through his blood”
Ephesians 1:7

“In him we have obtained an inheritance”
Ephesians 1:11

“In him you.... were sealed with the promised Holy Spirit”
Ephesians 1:17

“God... made us alive together with Christ ... raised us up with him and seated us with him in the heavenly places in Christ Jesus.”
Ephesians 2:4-6

Where do we have to be to receive God's blessings? In Christ. How do we receive God's blessings? In Christ. Where do God's blessings lead? Into Christ.

“speaking the truth in love, we are to grow up in every way into him who is the head, into Christ”
Ephesians 4:15, ESV

Or see 1 Peter 1:8, where the Christians to whom Peter is writing are said to believe into (εις) him.

Tenses

This brings us back to the idea that our union with Christ is something which is ongoing – it is true in the past, present and future. We have been crucified with Christ (Galatians 2:20), therefore we should be dying to ourselves (Colossians 3:5), and we will one day die in Christ (1 Thessalonians 4:16), unless he returns first. We have been raised with Christ (Ephesians 2:5-6), we are being raised in Christ (2 Corinthians 4:10) and we will be raised in Christ (Romans 8:11).

As Paul says in 2 Corinthians 4:

We are ... always carrying in the body the death of Jesus, so that the life of Jesus may also be manifested in our bodies. For we who live are always being given over to death for Jesus' sake, so that the life of Jesus also may be manifested in our mortal flesh.
2 Corinthians 4:10-11, ESV

This is then wonderful grounds for our assurance. We are in Christ, who lives forever. So when (and if) we finally die, we remain in Christ and so still live. That means that we have a sure and certain hope of the resurrection, because Jesus has been raised and we are in him, as Paul argues in 1 Thessalonians 4:16 “the dead in Christ will rise first.” (cf 1 Corinthians 15:17).

Jesus and Union

But it is not just Paul and Peter. Jesus also speaks about it at length in John 14 and 15, where we see that it is all intertwined with what it means to be indwelt by the Holy Spirit and with the relationship between the members of the Trinity.

“In that day you will know that I am in my Father, and you in me, and I in you.”
John 14:20, ESV

At the start of John 15, we also see that being in Jesus is the key to being able to bear fruit, and that those who do not abide in him are ultimately thrown into the fire and burned (John 15:6).

Colossians 3:3 - "Hidden in Christ"

So, to come back to one of the questions that prompted this, what does Colossians 3:3 mean when it says “For you died, and your life is hidden with Christ in God”?

This whole idea of dying with Jesus and rising with Jesus is a big theme in Colossians 2 (e.g. v12-13). Paul goes on to apply it in 2:20 – that because we have died to the “elemental spirits of this world”, we shouldn't be living worldly lives (in this case submitting to silly rules). Instead (3:1), Paul tells them they have been raised with Christ, and therefore should be setting their mind where Christ is.

That's the context for 3:3, so in context Paul is telling them that their primary identity is in Christ. After all, they have died in him, and have been raised in him. They are only really alive in him. Christ is where they are, so that's where they should be focusing.

The “hidden” refers forwards to v4 - “When Christ who is your life appears, then you also will appear with him in glory.” Their new, risen, in Christ, selves are not obvious. It will only become clear who we really are when Christ appears, and us with him (cf Romans 8:19). For the time being, what is in Christ is hidden.

1 Corinthians 6 and Sex

Another application of this is in 1 Corinthians 6, where Paul links the idea of our union with Christ with the idea that sex is an expression of and brings about union between man and woman. Paul therefore argues that for someone who is united with Christ to be united with a prostitute is crazy. Of course, the linking of union with Christ and union in sex both point forwards to the perfect consummation of the union between Christ and his bride the Church that awaits us in heaven.

Summary

Union with Christ is the means of our salvation – God counts us as righteous because and only because we are in Christ. We are raised from the dead both spiritually and physically only because Christ has been raised from the dead and we are united with him.

Union with Christ is the goal of our salvation. We are growing up corporately into him, and one day we will be perfectly united with him. This means our current union with Christ gives us a sure and certain hope for the future, because we know that what happens to Christ will also happen to us, just as what happened to Christ in his incarnation, rejection, suffering, crucifixion, resurrection and glorification is also happening to us.

Union with Christ gives us our identity - if we are in Christ, we are who we are in Christ, and nothing else.