You know the commandments. ‘Do not murder. Be faithful in marriage. Do not steal. Do not tell lies about others. Do not cheat. Respect your father and mother.’ ”
In the Law there are many commands, such as, “Be faithful in marriage. Do not murder. Do not steal. Do not want what belongs to others.” But all these are summed up in the command that says, “Love others as much as you love yourself.”
The same God who told us to be faithful in marriage also told us not to murder. So even if you are faithful in marriage, but murder someone, you have still broken God's Law.