Not the only page tradition that the Church stole too, Jesus wasn't born on Christmas Day, he was born in March.
"Both Mithras and Christ were described variously as 'the Way,' 'the Truth,' 'the Light,' 'the Life,' 'the Word,' 'the Son of God,' 'the Good Shepherd.' The Christian litany to Jesus could easily be an allegorical litany to the sun-god. Mithras is often represented as carrying a lamb on his shoulders, just as Jesus is. Midnight services were found in both religions. The virgin mother...was easily merged with the virgin mother Mary. Petra, the sacred rock of Mithraism, became Peter, the foundation of the Christian Church."
Gerald Berry, Religions of the World
There are many parallels between Jesus and Egyptian gods Osiris & Horas too:
Halloween was a Celtic festival and has been rebranded in Christian countries as a 'Day for all Souls'
en.wikipedia.org/wiki/Halloween
Even the idea of transubstantiation, the crux of the Catholic mass, isn't originally a Christian idea. The same goes for the virgin birth. They were all lifted from other previous religions.
Some religious scholars even claim that during Jesus' missing years he studied as a Buddhist monk, many of his parables and stories certainly share many, many similarities with Buddhist teachings.
Do your own research and make you up own minds, don't mindfully swallow everything the Church(es) tell you.