What shall we do about theists?

[Hezekiah]

This kind of thread is why Christians fear and distrust atheists. It's not funny to talk about rounding people up and putting them in death camps. Atheists have a bad history of actually doing this.

I agree with you and I understand your concern, but try not to take it that way. Instead use this as an opportunity to peacefully voice how you would like to see atheist and theist interactions play out.

In response to the question at hand: whether you're religious or non-religious, the most mature and peaceful way to deal with someone of a different worldview, is to simply remember that the individual is human being, seperate from the values they hold dear. You don't have to agree with their beliefs, but a person's beliefs should never out-weigh their value as a human being.