What if all the religions are wrong and god is pissed off because everyone's idea of deity is incorrect? What if you are wrong, and you've spent your time, your career, your finances, your entire life advocating a fantasy while those atheists and freethinkers you have been trying to "save" have been the ones with the firm grasp on reality this whole time? Reality is mysterious and inspiring enough without fantasies and delusions, and there are enough real problems in our world removing the need to create imaginary problems.
What if I'm wrong? Then I hope god or whoever/whatever is out there is intelligent and rational and compassionate and empathic enough to understand the limits of our understanding, that I and many others like me would have believed if we had only seen reason to believe, that many of us used to believe, and didn't step away from faith because we wanted to, but because we saw it was the right thing to do.
If you are wrong, you waste the lifetime you have on your delusion, hoping you have picked the right one. If I am wrong, I enjoyed the life I expected to have. If I am wrong, and God has some eternal damnation in mind for me, based not on who I was and how I acted, but rather on some unsupported belief in something that my rational brain just couldn't maintain, then damn him. Who would want to worship such a God anyway?