As my marriage fell apart, my wife became more religious, giving more and more time to various functions of the church. It definitely didn't help the situation at all.

I've been a non-believer for ~5 years, the marriage was on the skids long before that.

I guess It's possible but would be hard. My "husband" was married to his highschool sweetheart before he met me. Neither of them religious but after they were married about a year things changed. A neighbor started preaching to his wife about god and taking her to church, ect. Before he knew it she was converted to Christianity. He even went to church a few times to appease her. When ever they got into a fight she was always throwing god in. Blaming his lack of love for god, being the reason for his "problem's". She had none because she found the light and was now saved. He said it felt like living with Satan himself, lol. He realized real quick that she went over the deep end and they soon divorced. Unfortunately they had two children by then and she did not let him have a say in anything. The children soon were just as brain washed as she had become. It's been 19 years and she is still the same way.

Tried it for a year after my divorce. He had studied for the priesthood, was a victim of sexual abuse by a cardinal and had many problems. We went to a Unitarian Universalist Church to appease his religious guilt. It ended within a year.

I've never been with a believer

I was in a 3 year relationship with a believer. We basically agreed to disagree. We decided that how we treated each other was more important than our beliefs.

My best friend in hs was a believer and it never got in the way of our friendship

My experience is not good. An old, respected, and trusted friend (who was always religious) became more and more fervent in his old age (and more and more to the extreme political right). For many years we had supported and aided each other in our professional pursuits.
But, in r3cent years, he became more and more e fervent evangelical (and more and more to the extreme ,irrational political right), and he bombarded me with in incessant stream of religious issues and conversion attempts, mixed with extreme po9litical tracts. I was forced to tell him that I will no longer discuss religion, politics, or economics with him. He quit only I failed to respond to him on a number of pointed transmission. We now communicate only rarely. I valued our friendship.

I think strong ideals on either side not shared by the other puts a devastating strain on the relationship. I'd be hesitant to date anyone whose level of belief was more than that of "hopeful agnostic." I'm not saying it's never worked out, but that's a massive obstacle that's difficult to overcome.