Someone who puts god ahead of their partner will get exactly what's coming to them.
A partner who ranks below god (or whatever else ranks higher than them) will eventually resent the low ranking, the things that rank higher, and the other partner in the relationship who adheres to that ranking system.
I sometimes feel that trust between partners can never be complete in a relationship of that kind. You just never know when "god" is going to compel them to do something that is not in your best interests. Like donating an inheritance to the church (god) instead of saving for your kids' education or for your retirement. Like giving up a good job and decent income to Serve Where The Need Is Great™ or Pioneer™. Like refusing a blood transfusion when you or one of your children are unconscious and bleeding out, knowing full well that you would accept one if you were given the opportunity to consent.
Or when you can't fully enjoy intimacy with your partner because you are being constantly reminded that god / jesus / the angels / 144,000™ are observing your every move and know your heart and intentions while thusly occupied.