I found yesterday's quiet day very helpful. One of the passages that was spoken on (albeit briefly) was this bit of Hebrews 13. Some of what follows is what was said. Some of what follows are my own thoughts. All the mistakes are mine.
We have an altar from which those who serve the tent have no right to eat. For the bodies of those animals whose blood is brought into the holy places by the high priest as a sacrifice for sin are burned outside the camp. So Jesus also suffered outside the gate in order to sanctify the people through his own blood. Therefore let us go to him outside the camp and bear the reproach he endured. For here we have no lasting city, but we seek the city that is to come.
Hebrews 13:10-14, NIV
The significance of things being done "outside the camp" is a reference back to Israel's wanderings in the desert. Things that were somehow unclean happened there - executions, toilets, and so on. People with infectious diseases were sent there, as were other people in "quarantine" for coming into contact with dead bodies, etc.
But "outside the camp" was also where the remains of sacrificed animals were disposed of. And the author to the Hebrews is picking up on that idea too. Jesus, as the perfect sacrifice, was outside the camp. So going to him means leaving the camp - in a sense, losing all our affiliations and ties, being willing to be on one's own (in a sense) and to be rejected by society but to gain Jesus. Jesus is the one who is outside the camp.
That then links in to another big theme of Hebrews - the idea that we don't have any real home, any lasting city, this side of eternity. So to be at home in Jesus means to renounce our worldly ties.
That doesn't necessarily mean coming out from the world in a physical sense - it doesn't mean I have to leave England (for example), but it does mean I have to stop seeing my identity as primarily English. On a church level, it means that I have to stop seeing my identity as primarily evangelical (for example). Camps are things that we're meant to leave to follow Jesus.
On a similar note, Dan Edelen wrote a very good piece yesterday about our obsession with labels, and why it's a bad thing. Here's his conclusion:
I'm sick of labels, personally. I'm a Christian; that's the only label I wish to be known by. As to other labels, Jesus offers nothing but rebuke. The older I get, the more I understand that truth.
Time to stop the obsessive labeling. We're only hurting the cause of Jesus Christ by loving our labels more than each other.