Joan, it sounds as if you & I had similar experiences with husbands who after some time just turned away from being the men of faith they were. It's just so hard to tell how a relationship will progress. I look wistfully at those couples who have been married a number of years & seem to still be in love with each other, those who are sitting next to each other in the pew during Mass. I want to know their secret is to staying faithful to each other & to their faith! Realistically, all relationships can be so different depending on life circumstances & on the individuals themselves. Keep praying for each other & with each other on a daily basis could be the secret or at least part of it. It's certainly something to ponder because we cannot see down that road.
What I have come to find out is that the couple who "seem to still be in love with each other and sitting next to each other in the pew during Mass" struggle just as much as everybody else, married or divorced. The difference is how they respond to a difficult situation. My former spouse definitely hit the "midlife crisis" hard when he turned 40 (bought Harley, joined Harley gang, ect.). THere is absolutely nothing that I did or said that would change any of his choices. I moved forward in my life, spending the time that we would normally spend together in prayer. I also continued my education to increase my take home pay, in anticipation of having to support myself and possibly the kids. The additional prayer time allowed for me to reflect on God as my "husband", protecting me from evil and taking care of my needs. Fortunately God is always faithful and was able to give me the strength and intuition to do what was best for me and our kids. According to scripture it is better to remove yourself from an unfaithful non-believer than it is to stay in their presence, which is the choice I made.
The shared faith journey is a GIFT to those who are faithful. If one partner strays, the other one is called to continue on without them and not be pulled into the distruction of the nonbeliever. We are on this faith journey with GOD as our partner; he is always faithful, always present and will never do us harm.