>Christianity comes from JudaismIts actually the other way around.
Back in the day there was no Judaism, just the faith of Abraham and later the Israelites. At the time Jesus came there were 3 main sects, The Essenes (The only ones native to Judeah), the Sadduccess and the Pharisee (both being not native to Judeah).
The Pharisee are the Edomites (descendent of Amalek which the Israelites were told to genocide and which descent from the Canaanites which worshipped Moloch and such) which previously were forced to convert. However they really liked their old customs which were unlawful and thus they created the Oral Law. You know how in Court a Jew will use semantics, grey areas, loopholes and other pilpul to argue they didnt break a law which they never followed completly ignoring the intent behind the law? The Oral Law of the Pharisee is a guideline on how to do that with the OT Law.
This is the group of people pretty much all quarrels Jesus had was with and they were constantly rebuked for this by him, God himself, for being hypocrites, a brood of Vipers, even the children of the devil. Even their name describes them seperating themselves from the original
https://en.wikipedia.org/wiki/Pharisees>"Pharisee" is derived from Ancient Greek Pharisaios (Φαρισαῖος),[8] from Aramaic Pərīšā (Hebrew: פְּרִישָׁא), plural Pərīšayyā (Hebrew: פְּרִישַׁיָּא), meaning "set apart, separated"So by all means the Pharisee splitted themselves off from the original faith which became known and was continued through Christianity and thus by all practical means was Pre-Christ-Christianity.
This Oral Law of the Pharisee then after a few 100 years got written down in the (Babylonian) Talmud starting what is now known as Judaism. So its not that Christianity is based on Judaism, but that Judaism is a collection of blasphemies and herasies of Christianity