chapotraphouse

Paul converted Gentiles, the Johannine school was likely mixed, and the First Council of Jerusalem was largely about the independence of Paul and the lack of a need for Gentiles to follow Jewish Law. By 150 the vast majority of Christians were non-Jewish in ancestry. Many of the 1st/2nd century Church Fathers, like Irenaeus, Clement I, and likely others were non-Jewish. You also had non-Jews worshipping the Abrahamic god for at least the 1st century BCE

You can generally break down the early branches of Christianity into three cross pollinating branches

Jewish Christians - Lead by the moderate Peter and the more strictly Jewish James. Largely died out or was subsumed by other branches.

Pauline Gentile Christians - What became the main branch of Christianity in organisation.

Mystic Christianity - This includes both the Proto-Gnostics and the Johannines. Highly mixed in with other mystic/apocalyptic Jewish and Middle Platonic sects, and largely comprised of fairly educated Hellenistic Jews and Gentiles.

Their relative education and theological hot-housing meant that the Johannine school ended up cross-pollinating with the Pauline school and almost co-opting their theology (the Johannine Irenaus and composite theology of Justin Martyr shooting down the "hyper-pauline" heresies of Valentius and Marcion.)