As a Christian, many of us have been taught that God hates divorce. Not every marriage is blessed. God does not call holy that which is unholy.
Some marriages have been bad from the start and some have become unclean as time has gone by. Alcoholism, drugs and pornography are common problems that cause a spouse to be unclean. People live and die without God blessing their marriages. They stay in the marriage because they have been taught that God hates divorce. In reality, God is more for the divorce than the marriage at this point. But don't forget that only He can change the heart of the unclean person if that person calls out to him.