"Thou shalt not commit adultery" (Exodus 20:14).
"Know ye not that the unrighteous shall not inherit the kingdom of God? Be not deceived: neither fornicators, nor idolaters, nor adulterers, not effeminate, not abusers of themselves with mankind ...shall inherit the kingdom of God" (1 Corinthians 6:9-10).
G. Campbell Morgan said, "The adulterer is the enemy of the state. My personal persuasion is that it is an act of treason to the state to allow adulterers and adulteresses to go free and unpunished. The greatness of a people depends upon the purity and strength of the people, and in every nation where the marriage relation is violated with impunity the virus of death is surely and certainly at work."