Littletoejam,
I believe that the marriage arrangement is a covenant "here below" that shadows the covenant "above". Hence once we enter into that "spiritual" marriage it's binding. God doesn't divorce, would seem to be the biblical message, as further evidenced with his dealings with Israel.
What if a person questions the whole bible deal, then in his/her heart they cannot accept it any longer as truth, ...yet at onetime they were married in christ?........I mean reeeeeeally married? Can you leave? Would it be better to stay....or leave it? Now there's a toughie.
Gumbaffoon