Jesus is a Roman god. The current presentation of the Jesus myth was codified by the Romans in the 4th century.
The Romans were good at this. They recognised early that when they were planning to add territory to their empire (which they largely did by trade), they would show the locals that the god of the local lake was an aspect of Neptune. It made them less like strangers. If you've been indoctrinated from birth to believe in myths, it's hard to be enemies with people who share the same myths.
Of course later you have to have wars because the other lot aren't worshipping Bacchus properly.