The amazing thing is that hundreds of millions of people think like that. Literally hundreds of millions of humans can't get their minds past the imaginary.

You don't owe them an explanation, and you don't owe them enlightenment. In fact, it's hard to say they shouldn't proselytize you when you are, effectively, proselytizing them. Let them be as they are, so long as they leave you alone. If the people you are engaging with are trying to correct or convince you that you're in error, put up healthy interpersonal boundaries and enforce them, and then find people who don't do that to you to spend more time with.

In my opinion, they feel that there is a war on Christmas because the facts are overwhelmingly mounting against them and, deep down, they know your right. They can sense their crutch being taken away. They realize that it is only them and no God, or son of said God, there beside them and they cannot function without that thought. It's too engrained into their life to live without and that terrifies them.

Most of the so called Christians are very uneducated when it comes to the bible,they only know what the priest tell them.

I used to argue with them out of boredom. I don't get 'that' bored anymore.
Besides, nowadays, it's way more fun to troll the trumptards.
Sometimes, you get the twofer. That's always super fun!

Yes, the spirit is nice. Yet, also remember that it was Pope Julius 1 that moved Christmas from March to December.

Sweet spirit, save your strength and sanity: those who would respond in a constructive fashion to your challenging facts (true as they may be) are few and far between.