"He said to them, 'Because of your hardness of heart Moses allowed you to divorce your wives, but from the beginning it was not so.'" - Matthew 19:8
Loopholes! Our entire legal system spends massive dollars and hours seeking various "loopholes" to allow loose behavior. The laws that were intended to bring order and stability to life seem to be unacceptable to our self focused nature. The truth is; right living rules are hard because sin sick hearts are hard.
The institution of marriage was and still is abused and mistreated. In today's world, the marital vow, as many promises and contracts of life, are breakable. Moses allowed divorce, but from the beginning God intended the wedding vow to be life long. As a matter of fact, the Lord expects us to keep our word in every circumstance. So, why aren't we faithful? The answer is simple; hard sin-sick hearts.
The best rule of life is to look for God's heart in every promise and be faithful my friend. The Lord's original plan intended that our marriages were meant to last. Loopholes were never part of a God honoring life. Remember the words of Solomon in Ecclesiastes 5:4-5, "When you vow a vow to God, do not delay paying it, for he has no pleasure in fools. Pay what you vow. It is better that you should not vow than that you should vow and not pay."