No less than three of the Ten Commandments—the fifth, seventh, and tenth—directly involve strengthening marriages and families and preserving their unity and sacredness. Of course, all of God's commands, if followed, will work to strengthen man's relationship with God and fellow man, but these three are aimed directly at securing these sacred bonds. When considering any of God's commands, we find that they are broad in scope and ordained, not just to regulate our physical relationships, but also our spiritual one with Christ.
The fifth commandment speaks directly to parents and children, laying the foundation of responsibility that each has to the other. When children submit to their parents, and parents provide a loving environment to nurture their children in lawful living, the children and society directly benefit from this command. Home government is the cornerstone of national government, and when the home is right, the social structure follows. When marriage and family unity are held in high esteem and a fear of violating God's standards is instilled, sin can be held in check. Hebrews 12:11 declares, "Now no chastening seems to be joyful for the present, but painful; nevertheless, afterward it yields the peaceable fruit of righteousness to those who have been trained by it."
The seventh commandment—forbidding adultery, unfaithfulness by either spouse—stands against anyone who would defile the sanctity of the marriage covenant through sexual sins. Adultery is probably the most dishonest act against the binding contract of the marriage relationship; it is a betrayal of a most sacred trust. Not only is it a sin against one's companion, but as Paul teaches in I Corinthians 6:18, it is a sin against one's own flesh. It has destroyed many marriages and families. A marriage can stand against many adversities from without, but this sin destroys it from within, and few, if any, marriages can truly recover from such infidelity.
Jesus says in Matthew 5:28 that adultery begins in the heart. It is more than an outward action, but a lust that comes from within. Christ teaches us how broad the law is, and sexual acts outside of the marriage covenant—even just the desire for them—breaks this command. In other words, if the desire is there, yet only lack of opportunity has kept a person from this sin, the law has still been broken.
The tenth commandment—"You shall not covet your neighbor's wife" (Deuteronomy 5:21)—is likely a precursor for warnings against many other sins. It defends against anyone who would come between a man and his wife, and like the seventh, its breaking also begins in the heart. Unlike the seventh commandment, which looks to protect the marriage from within, in the tenth commandment God protects it from without.
Strong marriages can stand up to outside pressures of this sort, but weak marriages that are battling other issues may not. How many marriages have been defiled or destroyed by the coveting of another cannot be known, but since God included it in the Ten Commandments, its potential harm against the sacred bond of marriage must be high.
When he coveted Bathsheba, the wife of Uriah, King David assaulted the marriage covenant, and disaster soon followed. Breaking this commandment led to adultery and then to murder. In our society today, similar lusts are leaving destroyed families in their wake.