Do you seriously not know?
Wikipedia, while not always accurate, is a good source on the topic.
A lot of texts in the NT are written by Paul [Saul] of Tarsus.
He was a major person in the conversion of many 'goy' [non-Jews].
Paul was reasonably well educated and a Jew [pharisee].
The gospels are anonymous, despite being "according to Matthew" etc. according to scholars.
The Nag Hamedi library also provides some insight into the various beliefs around in the first few centuries AD..
Jesus is a real person, and it is independently verified [not Bible] that it "was believed" that he was crucified. i.e. died on a cross/stake
Any questions?