Atheists haven't tried faith? I think you'll find most adult atheists were raised theists as children by their, equally conditioned to 'believe', theist parents.
Atheism isn't simply an arbitrary rejection, it is an intellectually honest position.
Most adult atheists today have got to that stage after having spent a considerable amount of their lives trying to make sense of the theist world-view and ultimately reaching the correct conclusion that theism, in that it requires intellectual dishonesty to be maintained, isn't actually knowledge of anything but is instead the process of giving yourself up to arbitrarily declared dogma derived from a time in our species when we weren't able to understand much of anything.
Shit, all you have to do is look at Scientology to see how, even today, people are often incapable of even the most basic reasoning skills and will latch on to truly outrageous and absurd claims being made by organisations and people who claim to have the answers to the questions of life for them.
That is because they have been raised to believe that someone, somewhere, has the answers they need. The truth is we all are perfectly capable of reaching the most intellectually honest conclusions about life, The Universe and Everything, without resorting to "therefore God . . ."
That what theists absolutely hate about atheism - because it doesn't say, "trust us, we're telling you the truth" like theism does, no, it actually says, "trust yourself, you can figure out the truth".
Theists are far more likely to get on with people of other faith because they're all part of the same game of playing-pretend *real* hard and us atheists are like the grown-ups who are spoiling their fun. Trouble is their 'fun' is deadly and toxic.