I Were Free to Get Married, but She Chooses Not To

The book is about two people who fall in love, but understand themselves to be immortal beings. When one understands oneself to be an immortal being, the decisions that they make in love and life are slightly longer term. The idea of god having a plan and providing for his creatures is something that features very strongly throughout the novel. I think he wasn't quite ready, spiritually to to marry her, but he is by the end. But it has a happy ending, and they do get married.