I was very intrigued by reading 1 Cor 7:20 "Each one should remain in the situation which he was in when God called him" this morning. In that passage Paul is arguing that there are a number of things that should not be changed when you become a Christian. This is very interesting because so often I, and perhaps others as well, would naturally stress everything that does change when you are born again. Yet, here, Paul is saying that there are things that do not change, such as what you do, your social position and your marital status. Of course, this is in many ways obvious. But, as I thought about it, it struck me that it is theologically important to say that some things do not change when you are born again because that helps define what being born again actually means.
So, if my social position changes then being born again is political revolution. If my marital status changes then being born again means that I have already been resurrected in the new creation. If my culture changes then being born again is a tool of imperialism. Saying what being born again does not change actually helps to define what being born again does mean. It hinders confusion, distortions and add-ons. That is why Paul says circumcision (v.19) does not matter. It is irrelevant. Whereas if you argue that being born again does mean circumcision then essentially you must become a Jew to be saved.
This obviously has lots of spin-off implications for evangelism, mission and church-planting.