Everything we read about Jesus had to be put in two contexts. One is that if such a person lived where it is claimed he lived, he was an orthodox Jew and nothing else. Another is that whatever is attributed to him we can assume was actually the voice of the unknown authors writing after Jesus was dead.
What the Bible shows is that the authors portraying Jesus’ life as a preacher seemingly did not want him converting gentiles to Judaism. There is no specific reference to such preaching by Jesus in the four cannon gospels.
The reason people believe Jesus was gung ho about converting the Gentiles is the passages attributed to him after he came back to life. Then, and only then, he told his followers to preach to the world. Further, he said anyone who failed to believe was doomed to hell.
So, the question is this. Why did the writers not have their Jesus character preaching to Gentiles early on? Why did they have Jesus telling his followers to preach to Gentiles when he, himself, did not do it?
My theory is that the original writers had in mind a pure Jewish society in which there was a local hero. As time passed, the goal of the movement changed. By the time the hand written texts had been recopied for years, the broader mission was inserted.
The texts were changed to have Jesus advocating for converting Gentiles. When the gospels authors wanted to deliver some important message, they would insert it in the quotes from Jesus.
[A Christian’s view of Jesus and the gentiles can be linked in comments.]