Yeshua and his first followers remained Jews within Judaism. There was no separate path formed by them. These were Jews who believed Yeshua was in a messianic role according to Jewish tradition — “oral Torah.”
It is critical to understand that their approach to understanding the Hebrew Scriptures was within that framework of Jewish Torah spirituality.
As recorded in the gospels, Yeshua said he came only for B’nei Y’Israel. He did not teach gentiles. He told his immediate disciples not to go to the gentiles as well.
He taught his fellow Jews regarding teshuva – return to Torah.
In response to another (Samaritan) interpretation of the Torah, he told the woman at the well that her people did not know what they were talking about. When the Sadducees challenged him with a question in Matthew 22, his detailed response was from oral Torah.
HOW and WHAT did these gentiles learn? It wasn’t from any foreign perspective. The synagogues were run by the Pharisees. They were taught from within that same framework of Torah Judaism — the same as if anyone studied in orthodox Jewish circles today.
This does not mean gentiles had to become Jews. It means the BASIS of understanding and their role in God’s plan was all according to the spiritual framework of Judaism, the written and oral Torah. The council in Acts 15 affirmed this, directing gentiles to the synagogue system, which was run by the Pharisees.
“Caesar and Christ,” Will Durant, 1944, Simon and Schuster, New York, p. 616.