Peter knew that Gentiles were accepted into God’s family. Acts chapter 10 tells the story of how God showed that to Peter. But there were Jewish believers who didn’t approve of this. They thought that Jewish believers should stay separate from Gentile believers. They challenged Peter.
Peter started treating Gentiles as outsiders. He no longer treated Gentile believers as his brothers and sisters in God’s family. Other Jewish believers like Barnabas followed his example. They treated Jewish laws as more important than following Jesus together with other believers.
Paul strongly disagreed with Peter. He corrected Peter in public. Then Paul wrote to the Galatians about the law. He was talking about Jewish laws that separated Jews from Gentiles. This included laws about circumcision, food and honouring the Sabbath day. Paul made it very clear that obeying these laws doesn’t make people right with God. Only Jesus can free people from sin’s power and bring them back to God.
Paul described this as if believers are crucified with Christ. This is a picture of how closely believers are joined together with Jesus. Paul wasn’t saying that believers are nailed to the cross. Only Jesus was nailed to the cross and died to save people from sin. Paul was describing something about believers. They no longer live in the sinful ways they used to live in. Those old ways of living are dead. Now believers have new life from Jesus. They don’t receive this new life by obeying the Law of Moses. They receive it from Jesus. It’s a gift because Jesus loves all people.