Jesus believed that he was the messiah.
There were two types of messianic "candidates" in 1st century Judaism. One type sought to free Judea from Roman rule and to restore the earthly kingdom of David (bar Kokhba, for example). The other sought a "new heaven and new earth" -- the kingdom of God -- that would be brought about by God's intervention rather than by force of arms. Jesus was of the second type.
Jesus's disciples believed in his resurrection and imminent return.
The early Nazarene community contained both pacifists (who thought that all they had to do was to await the imminent return of Jesus) and the activists (who thought that they needed to continue the struggle against Rome).
As long as the Nazarenes believed in Jesus as a human messiah, they were not believing anything that was outside the bounds of Pharisaic Judaism. Even a belief in Jesus's resurrection and return would not have divided them from non-Nazarene Judaism.
The Nazarenes and the Pharisees actually got along well. The Nazarenes did have problems with the temple Sadducees and the high priest.
Some of the players: pacifist and activist Nazarenes. Pacifist and activist Pharisees. The Essenes, who were an opposition group of Sadducees. The Herodians, who were of a mixed Jewish and Edomite background, and who collaborated with the Romans. And the temple Sadducees and the high priest, who were also Roman collaborators.
The gospels were written after Paul's epistles.
Galatians is the most important book in the Christian canon.