"Marriage is like a dance. There is constant movement and change. One certainly is not married to the same person as he or she married ten years previously. So being married is a constant process of getting married and of finding appropriate ways of saying "I love you" at each stage."
On contentment in marriage:
"The great sin in our callings (such as marriage) is the lust of the spirit - discontentment, coveting someone els'es calling as better than one's own. The solution for this is to practice thanksgiving and to labor to see that God has given us what we need and that God (not a perfect situation) is our portion (Ps 73:26)"
-R.Paul Stevens "Down to Earth Spirituality"