It seems like the Hebrew Jewish Christians split, just after the last apostle died. The Apostle Paul writes in The New Testament that the Jewish Christians and the Gentile Greek Christians were United as one group.
Yes.
Does anyone know the name of this group? That consisted of Hebrew Jewish Christians and Greek Christians after the last Apostle died?
The original Apostles were all Jewish, what happened to this group? And what were their beliefs in the first and second century?
And were they considered heretics by the Greek Christians?
There were a number of proto-Christian groups in existence ... for example John the Baptist's influence was far reaching, and then we have the 72 disciples sent out to preach in Luke 10 – so we have Christians preaching in the world before the Passion, before the final revelations, as it were, that only came to light after the empty tomb.
If you read Acts 18, we have Apollos, "Now a certain Jew, named Apollos, born at Alexandria, an eloquent man, came to Ephesus, one mighty in the scriptures." (18:24) So an educated Jew well steeped in the Hebrew Scriptures. "This man was instructed in the way of the Lord ... and taught diligently the things that are of Jesus, knowing only the baptism of John" (18:25).
So Apollos is a Jew, a convert to Christ, according to the preaching of John the Baptist – so his 'Christianity' would be different to that of the Apostles, and different to that of Paul, who underwent his own 'Pentecost' on the road to Damascus. Apollos would understand Christ as Messiah in a Mosaic context.
"Whom when Priscilla and Aquila had heard, they took him to them, and expounded to him the way of the Lord more diligently (that is, the post-Resurrection teaching)" (18:26)
Acts 19 we have Paul in Ephesus: "And it came to pass ... that Paul ... came to Ephesus, and found certain disciples. And he said to them: Have you received the Holy Ghost since ye believed? But they said to him: We have not so much as heard whether there be a Holy Ghost. And he said: In what then were you baptised? Who said: In John's baptism. Then Paul said: John baptised the people with the baptism of penance, saying: That they should believe in him who was to come after him, that is to say, in Jesus. Having heard these things, they were baptised in the name of the Lord Jesus." (19:1-5)
Here we have Paul finding a Christian community in Ephesus, who heard the preaching of John the Baptist regarding Jesus, but had not been instructed according to the fulness of the Gospel ..
So we have Christians who being instructed not by the Apostles directly, would see Jesus as the Messiah in a Jewish context, and would see the Mosaic covenant as still binding.
There was obvious tensions, and some elitism, between Jewish Christians and Gentile Christians, the former regarding themselves as 'better' because they were Jews ... Paul struggled manfully to break this down, to show that it was not necessary for Christians to observe the Law to the letter, but not at the expense of the Covenant with Israel.
Not everyone believed, and there were groups who insisted that one had to be a Law-observing Jew to embrace Jesus.