The Pharisees were renowned for their strict keeping of the Law of Moses. Circumcision was the outward mark of being member of the People of God, so this demand by the Pharisees seemed perfectly logical. But there was so much more to it than that!
First, they held that to be a follower of Jesus a person had first to be a fully recognised Jew. Be a Jew first, then you can become a Christian! After all, Jesus was a Jew, so to follow Him you had to be like Him.
Second, a person could not be fully ‘right’ with God until he was circumcised.
So the debate must have been heated, and is certainly significant! Paul’s argument, and Peter’s too, was that if a person had received the Holy Spirit then he had become a child of God and a member of God’s Family, regardless of circumcision. Furthermore, Abraham had been declared ‘right’ with God on the grounds of faith, before he was circumcised. Paul sets this all out very clearly in Galatians chapter 3, which was written around the same time as this debate was going on. Faith, and receiving the Holy Spirit, was therefore the distinguishing mark of the Christian.
This debate is often referred to as ‘The Council of Jerusalem’, and the decision to admit Gentiles as full members of God’s people was a significant step in the development of the Church.
At last the promise made to Abraham to bless all nations through him ( Gen 12 v 3) was fulfilled! God’s purposes were recognised by these early Christian leaders and the all-inclusive nature of the Church was established. Today, we take this outcome for granted, although perhaps we still need to learn to welcome people of all backgrounds into the local church, and appreciate the diversity this brings.

For reflection: Are all kinds of people really accepted in our church?