I had a hard time with this one too, when I divorced. I was Christian at the time and it took me a very, very long time to come to the decision that I had to leave. I didn't want to give up at all, not only because of doctrinal issues, but also because - well, I'm just stubborn that way.
I didn't leave my spouse because he was a "loser". I ended up leaving because there basically wasn't ever any marriage to begin with. We went through the ceremony, signed the papers, and shared living arrangements, true. The thing that I found frustrating is that it's as if my now-ex just never actually got around to fulfilling the vows we took. It was almost like he acted like he had better things to do, and when he felt like creating a marriage relationship, he'd get around to it eventually.
You can really only bash your head against a brick wall so many times before you realize your brains are all over it. My spouse was a chronic stonewaller. It just isn't possible to have a relationship with someone like that. Believe me, I tried. I tried everything I could possibly think of and more, and y'know - I just couldn't make him connect emotionally. He was and is an extremely intelligent, capable individual, but I think he's so deeply stunted emotionally that at the time I certainly couldn't help him. It was better in the end to let him go. The quality of both our lives improved a hundredfold. Mine certainly did, and his seems to have done also.
But yeah, it was very hard. I've had all kinds of responses to my divorce. Some people have been totally sympathetic. I got a lot of support from family and many of my friends at the time. Others have been judgmental, kindly or unkindly. It was hard to face people at our church, and there were other friends I lost too. I've been told I disobeyed God, and I've been told that I did what was best.
In the end I just realized that regardless of what any holy book says, or what any church says, or really what anybody says, I valued the quality of my life more than anybody else's condemnation. I still do. If there are cosmic consequences I'll meet them, but I don't think there are - I think the consequences are limited to my lifetime and the lifetime of my ex, and I've already met those.
Anyway, just a personal anecdote. I dunno if it's worth anything, but there it is. Thanks for reading.