There are definitely elements of Christianity that mimic Greco-Roman (and other, older) mystery religions. Down to celebrating their deity’s birth at the same time and commemorating his death and rebirth by having followers share bread and wine.

My favorite theory of the origin of Christianity is that it was a Jewish attempt to mimic the mystery religions that were popular at the beginning of the Common Era.

My childhood bestie’s dad was one of the only bald men in our church. He pulled out this story every time anyone in our youth group mentioned it.