I thought atheist was a belief that there is no God, or Higher Power of any sort, but than someone explained to me that it can mean, just simply keeping an open mind.
Or, that could be agnostic, I'm not sure. I had a good conversation with them, and they are a very nice person.
So some people feel this way in an attempt to keep an open mind. And that is not a bad thing, necessarily, that can be a very good thing. Cause' they feel it gives them an expanded awareness because they are not closing there mind to only one way of thinking.
Still, others who once believed and changed they're beliefs, often might do so because they have let life wear them down.
Of course they didn't have to let other people, or life, do that to them.
But we shouldn't judge them, unless we have walked a mile in they're shoes, and we might do more miles in they're shoes then that someday.
So, there's the positive reason. That one is not an avoidance of a belief, or change, necessarily, but more of a conscious decision, maybe.
And the other is not always for such positive reasons. Then sometimes there belief comes back, or they may become more firm in the new beliefs they develop.
As for me, I believe in a higher power. For me I don't think my own life would have the same feeling without knowing there is something there.
I recognize others don't necessarily think the same way I do, but that is just fine with me and I have a totally equal amount of respect for them too.