Keep your eyes wide open before marriage, half shut afterwards.
-Benjamin Franklin
Relationship guru I am not.  However, I do realize a thing or two about relationships.  As for the things I did when I was married that were wrong or that I would do differently if it were possible—there are some things I’d never change—things I’d never do over, moments trapped in time I will never forget.  And I can’t take the credit—God was good to me.  It’s too late now to do anything different or take anything back—what’s done is done.  But, it’s not too late to reflect on the fact that I could have been a better husband with a little more love and a lot less finger pointing.  I could have sacrificed more and taken less.  I could have kissed more and talked less.  I could have forgiven quicker and looked for paybacks less.
 At that point Peter got up the nerve to ask, ‘Master, how many times do I forgive a brother or sister who hurts me? Seven?’  Jesus replied, ‘Seven! Hardly. Try seventy times seven.’   (Matthew 18:21-22, The Message Bible)
In John Michael Talbot‘s The Lessons Of St. Francis, Talbot writes Perhaps you need to begin forgiving someone who has hurt you in the past.  An unforgiving spirit blocks the flow of grace and mercy into our lives, causing us to drown in a stagnant cesspool of regrets, animosities, and grudges. 
Who do you need to forgive?  Is it a parent or sibling who slighted you?  Is it a friend or lover who hurt you?  Is it a priest, pastor, or teacher who took advantage of a position of trust and authority?  Is it a kamikaze driver on the freeway who terrorizes your morning commute?  A telemarketer who invades your dinner hour?
Forgiving someone doesn’t mean that what they did was right.  As Frederick Buechner writes, forgiveness is a way of saying:  ‘You have done something unspeakable, and by all rights I should call it quits between us.  Both my pride and my principles demand no less.  However, although I make no guarantees that I will be able to forget what you’ve done and though we may carry the scars for life, I refuse to let it stand between us.  I still want to be your friend.’
Talbot continues, Forgiveness simply means getting down off the seat of judgment and releasing those who have offended you from your hostility and anger.  And while you’re at it, ask God to forgive you for the ways you’ve let down Him and others.  Freed by forgiveness and energized by love, you can be a channel of charity, compassion, and grace in a hard and needy world.      
Forgiveness isn’t easy, but it is the key to a long lasting and fruitful relationship.  It can be heart-wrenching.  But without genuine forgiveness, there is no hope for a love that lasts a life-time. 
Forgiveness is the relationship glue.