This was the attitude of Joshua's baby-killers, and the crusaders, and the conquistadors, and the inquisitors and the Taliban and ISIS.
This is why theism is not just silly, it is dangerous and ought to be opposed and ridiculed relentlessly.
I might suggest that not all christians are murderers, from my observations.
Fanatics and extremists rain on any parade of course but these exist on most sides of a fence. That Stalin was atheist and killed millions for an ideology does not make atheism evil.
Is it the ideology or the person that makes something dangerous?