There are a few major practices that they Jews did that set themselves apart from the rest of the world. Two major practices were circumcision and their table practices. One of the biggest problems in the early church was that the Jews wanted the non-Jews to take part in these practices to make them set apart like they are as Jews. Righteousness comes through Christ and our identity is found in him, not in our practices.
It is easy to ignore these practices when you are in the minority. When your Jewish friends show up you are tempted then to segregate yourself from people who are not like you to distinguish with your friends that you are different (and above) the others. This is the hypocrisy that Paul is calling out in Peter. We are all one in Christ and are not to be divided by nationally different. There is neither Jew nor Gentile.
One of the early misconceptions about how the Jews thought about the Law was that you have to follow the Law in order to get into Covenant with God. The Jews understood that they were brought into covenant with God through His grace and justified by Him. It is observance of the Law that keeps them in this covenant. This is why Paul in v15-16 says that they who are Jews by birth “know that a person is not justified by observing the law” and now understands that it is through Christ that they are justified. If it is through God’s grace that the Jews were brought into covenant and not through Law observance, why would they tell the Gentiles who have been justified by Christ that they now have to observe the Law to belong? Now that they see it is Christ who justifies, why would they as Jews not put their faith in Jesus as well?
What do we learn from this exchange?
There are things that make us different from different groups of people that we will naturally want to divide ourselves on. It could be class, race, status, gender, etc. The more important ones that I feel like need to be pointed out are our politics. Some people will pray that we will elect a new leader who is Godly, which begs the assumption that the current one is not Godly. I then begin to wonder how my Brothers and Sisters who happen to be democrats feel about these prayers. I made a comment once about my friend being a democrat and a friend of mine responded, “I thought he was a Christian?” Is our national pride more important to us than our unity in Christ? No matter where you are in politics, you are a Christian first and your citizenship in the Kingdom is far more important than your citizenship as an American.
On another scale, when we send missionaries into the world they take the American church with them and tell them that this is the correct way to be a Christian, totally ignoring the culture that Christianity should be part of. One of my friends went down to drastically different culture than ours for short term missions and when he got off the plane he saw a lot of half dressed people walking around. When it was time for worship on Sunday, all of them men showed up in dress shirts with ties on and the women in long dresses. Apparently the church back in the 50s had taken clothes for them to wear on Sundays.
We need to be careful about what we allow to divide us as followers of Christ. Do we see Christians around the world as our Brothers and Sister equally or as below us in need of our help because they aren’t from the USA? We are one in Christ because Christ has justified us. Does anything else matter?
What is divisive in your life that needs to be crucified with Christ so that Christ can live in you? The life you now live, you live in the Kingdom of God, the Church, the Body of Christ. You live this life in faith because Christ brought you into it and you have no advantage over anyone else in the Kingdom.