When Jesus was asked about divorce, He told them about God's design for marriage – the joining together of a man and a woman together to become one new, unique and inseparable unit, ‘one flesh’ (Matthew 19:4-6).  "What God had joined together, let no one separate", said Jesus (Matthew 19:6).  However, some of the Pharisees believed that there was a provision for easy divorce in God's Law (Deuteronomy 24:1-4), and they pressed Jesus to explain the passage which apparently allowed a husband to write a certificate of divorce and send his wife away if she displeased him.  
 
Jesus looked behind the certificate to the attitude of the husband.  Instead of focussing on the failure of the wife to live up to her husband's expectations, Jesus exposed the heart of the husband as being hard, cruel and unforgiving.  That was not God's plan for human beings or for marriage.  In the beginning there was love and harmony in marriage.  But when sin entered the world, the first change was quickly seen when nakedness became a sign of shame (Genesis 3:7) instead of intimacy (Genesis 2:25).
 
The end-point of shame within marriage is either forgiveness and reconciliation, or divorce.  But Jesus removed the presumption that remarriage was the answer – affirming Deuteronomy 24:4.  Even where the marriage bond has been broken through adultery, it is still preferable to find a way to soften hard hearts.  Hard-heartedness is not just a marriage problem; it is a spiritual problem, which will continue even though divorce may leave a faulty marriage behind.  The hard heartedness of divorce does not come from God.  Whatever the outcome of relationship problems, there is no joy while hearts remain hard.
 
Whether you are married or not, get used to a regular discipline of being open to God about the state of your heart.  Let His Word diagnose your 'heart disease' and repent of hardness of the 'arteries' and 'muscles' of your spiritual heart.  Failure to deal with that will be fatal to relationships with others and God.  Instead of judging your spouse unfairly, examine your own heart and let the Lord do whatever is necessary to soften you so that He can use you to bless others instead of cursing them.