One of the questions I am most often asked in my capacity as person who knows something about theology is what the point of the Old Testament Law is for Christians today. I've got to do a lot of reading about this in the near future, so my opinions might change, but here's roughly what I think after however many years it is of thinking about it so far...
There are two main purposes of the Old Testament Law, and both of them function for us as Christians.
First Purpose - Modelling a Response to Salvation
The first purpose is to model a response to God's salvation. Exodus 19 and Deuteronomy are very clear that the Law was how the Old Testament people of God were meant to live in response to God saving them. Of course, it's going to be different for us now, for loads of reasons, the biggest of which are:
- We've got the Holy Spirit indwelling us now
- We know about Jesus
- We aren't a theocratic state but a group of Christians living in countries that aren't Christian
That means it's often going to be hard work applying aspects of the OT Law to us today. Some areas are easier for others. For example, one of the big areas in the OT Law is a concern for social justice, and though the categories of who are oppressed are different today (due to a welfare state, less respect for the elderly, family breakdown and abortion legislation among other things), some of the ideas are still applicable. An even easier example would be commandments such as "do not murder", which pretty much just apply straight (though the punishments don't necessarily, given the different nature of the state).
A more difficult example would be some of the food laws and ceremonial laws which are about showing how holiness applies to every area of life. The OT Law doesn't apply directly to us, but it's all still relevant if we're willing to do the work.
Second Purpose - Showing Us We Need a Greater Salvation
The OT Law also points forwards to Jesus. It shows us that we are sinful and need to be forgiven - that we continually need God's grace, the indwelling of the Holy Spirit and the forgiveness that comes by the blood of Jesus.
Civil, Ceremonial, Moral?
The traditional way of doing this (I think Calvin used it, but he might have got it from somewhere) was to split the Law into civil, ceremonial and moral, and say that the ceremonial law was fulfilled in Christ, the moral law is still binding and the civil law is a model for how society should be, or something like that.
I don't like that distinction, for the simple reason that it isn't in the Old Testament, and it ends up being an arbitrary decision of the interpreter which bits are which.
Much better to ask questions like this of the whole OT Law:
- How does this point forwards to Jesus?
- What does this tell us about God?
- What does this say about how we should respond to our salvation in Jesus?
We don't have to obey the OT Law - it has been fulfilled in Christ, but it can be very useful in showing what it meant for the Israelites to be God's saved people, and hence point to what it means for us.
The discussion continues here.