I'm a Christian. I said it before and will say it again: In a strictly historical context, Christianity is just a very weird sect of Judaism.
As rabbinical Judaism is broadly understood, it’s certainly a turn on the faith that none of the rabbis fully expected.
But it sure fits with Jesus being the ultimate Rabbi with the ultimate right to be that. Being part of the divine nature would place Him squarely in such a position.
The proof, as it is said, is in the pudding. Versions of Christianity that have given Jews historical grief inevitably are those which are acting in part (if not in whole) as Selfianity. This is a hazard that appeared in Pharisaical Judaism and a hazard that continues to be possible in Christendom.