How do you explain the fact that jesus' life and other gods through out time were based on the sun....?

The story of jesus, osiris, horus, mithris, and countless other deities were all based on the cycle of the sun. They all were born of the same day, died and were resurrected 3 days later, Born of a virgin (born when the sun is in the cycle of virgo. How can christians explain this and say their beliefs are true when the majority of their beliefs are just imilated pagan beliefs.....