I think that the spiritual journey doesnt end with atheism.
I view atheism as a stop on the way to a better understanding of self. When that happens, people tend to be better able to define "god" for themselves better.
Because atheism starts with a more accurate premise, I think it is a better place to start with (not seeing god) as opposed to organized religion (assuming the existence of god)
Who here has seen god?
How many assume the god that they were taught to believe in is the true god?
I don't think that atheists and theists are on the same team, simply because one place starts at a more honest point than the other.