The Cornelius episode (Acts 10), in which the Pentecost-like ecstasy affecting the Roman centurion and his entourage persuaded the astonished Peter to baptise them without further ado, seems to have been an exceptional event; no further conversion of a Gentile is recorded in the Holy Land anywhere in the New Testament. 

It was in the Syrian city of Antioch in the late 40s CE that the novelty set in. Emigré members of the Jerusalem church were joined there by Gentiles evangelised and baptised by Judaeo-Christians originating from Cyprus and Cyrene. The mother church of Jerusalem dispatched Barnabas to run the new mixed community, and Barnabas hurried to Tarsus in Cilicia to persuade his friend Saul/Paul, already a believer in Christ, to join him in looking after the new church. The Jewish and the Gentile Christians of Antioch coexisted happily and ate together. When visiting the community, Peter willingly participated in their common meals. However, when some extra-zealous representatives of the Jerusalem church headed by James the brother of Jesus, members of the so-called "circumcision party", arrived in Antioch, their disapproving attitude compelled all the Jewish Christians, including even Peter and Barnabas, but with the notable exception of Paul, to discontinue their table fellowship with the brethren of Greek stock (Acts 11:2). As a result, union, fraternity and harmony in the new mixed church was abolished. The outraged Paul confronted Peter and publicly called him a hypocrite (Gal 2:11-4), creating the first major row in Christendom.   

After Paul's first successful missionary journey to Asia Minor, the entry of pagans into the Jesus fellowship became a particularly acute issue. A council of the apostles, attended by Paul and Barnabas, was convened in Jerusalem, at which James the brother of the Lord, the head of the mother community, overruled the demands of the extremist members of his congregation and proposed a compromise solution (Acts 15:19-21). Gentiles wishing to join the church would be exempted from the full rigour of the Law of Moses, including circumcision, and would merely be required to abstain from food sacrificed to idols, from the consumption of blood, from eating non-ritually slaughtered meat, and from certain sex acts judged particularly odious by Jews. 

These rules were necessarily intended for Gentile converts in the diaspora. In Jerusalem different conditions prevailed, for Gentile Christians could not join their Judaeo-Christian co-religionists in the Temple as non-Jews were prohibited under threat of instant death to set foot in the area of the holy precinct reserved for Jews.