To begin at the beginning, the first reason I am an agnostic is that I was not raised to be religious. This is one of the minor reasons. I believe that if I were meant to be religious, not being raised in it would not have kept me from it.
I think some people’s commitment to religion comes in part from their fond memories and the secure feeling that comes from an association with family. Since I don’t have those associations, religion doesn’t have the same appeal for me as a Jew who has always been in a practicing Jewish family or a Catholic who went to midnight Mass every Christmas. There’s more, much more, but that was an easy one to start with.