Galatians 2:7

(7) Gospel of the uncircumcision—i.e., a gospel for the uncircumcised. The elder Apostles recognised St. Paul because they saw that his teaching was fundamentally the same as their own. At the same time, the success of St. Paul among the Gentiles proved that his mission to them had the divine sanction, just as the success of St. Peter among the Jews specially marked him out as the “Apostle of the circumcision.”