Pagan Origins of the Christ Myth
Another Sacred Penis for your Mother-in-law moment
The ancient world was incomprehensibly different from ours. It's hard to remember how different.  This helps:  
The Romans would go to the mixed- sex public baths completely naked.
For women followers of the Goddess Cybele, having sex with a stranger at the temple was a religious act -- a sacrament!
And, get this, you read in the ancient texts about a man, a follower of Dionysus, dedicating a sacred penis to his mother-in-law! Go figure.

You can't figure. I doesn't make sense -- to us. It did make sense to the ancients. That's the point. Ancient culture was different from ours in ways we would never predict and can't understand.

Keep that in mind while we talk about ancient religion.