Deuteronomy 22:22. The basic definition of adultery is from Deuteronomy 22:22. Adultery is “…lying with a woman married to an husband…” Adultery is any time a married person has sex with someone outside the marriage. God considers adultery a sin and it is one of the ten commandments (Exodus 20:14, “Thou shalt not commit adultery”). The punishment for adultery in the old testament was death for those who committed adultery (Deuteronomy 22:22, “… then they shall both of them die, both the man that lay with the woman, and the woman: so shalt thou put away evil from Israel”). Today, most of the world does not consider adultery a crime, much less a crime punishable by death. On the other hand, God's opinion about adultery has not changed (Revelation 21:8, “But the … whoremongers … shall have their part in the lake of fire which burneth with fire and brimstone: which is the second death”)

DEUTERONOMY 22 BIBLE SCRIPTURE: Deuteronomy 22:22, “If a man be found lying with a woman married to an husband, then they shall both of them die, both the man that lay with the woman, and the woman: so shalt thou put away evil from Israel."

2 Peter 2:14. The definition of adultery includes it being a sin in God’s eyes. Adultery is an unrighteous act. In no circumstances can it please God when you commit adultery. Adultery starts where you lust for someone that you are not married to. You are not pleasing to God when you are “girl watching” because this becomes a slippery slope that will lead to adultery. You are basically coveting someone else’s wife or daughter when you “girl watch”. In this case, your eyes are full of adultery and it is only a matter of time before you find a willing partner to commit adultery (2 Peter 2:14-15, “Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children: Which have forsaken the right way, and are gone astray, following the way of Balaam the son of Bosor, who loved the wages of unrighteousness;”).

BIBLE SCRIPTURE: 2 Peter 2:14, "Having eyes full of adultery, and that cannot cease from sin; beguiling unstable souls: an heart they have exercised with covetous practices; cursed children:"

Matthew 5:28. The definition of adultery includes the characteristic that it comes from within and it is not caused by outside influences. Adultery is committed by two willing partners. One person in the relationship may have been the temptress or tempter, but the other person accepted the temptation. Adultery is always birthed from our own heart. If you do not have adultery in your heart, you will not commit adultery no matter what the temptation. God knows that adultery starts in the heart and he considers us adulterers when we even think about committing adultery. When we have lust in our eyes for a person who is married to another, He considers us adulterers. (Matthew 5:28, “But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart”).

Adultery starts with our sinful heart. God considers adultery evil. The act of adultery defiles a person just like murder, theft, pride, and so on (Mark 7:21-23, “For from within, out of the heart of men, proceed evil thoughts, adulteries, fornications, murders, Thefts, covetousness, wickedness, deceit, lasciviousness, an evil eye, blasphemy, pride, foolishness: All these evil things come from within, and defile the man”).

MATTHEW 5 BIBLE SCRIPTURE: Matthew 5:28, “But I say unto you, That whosoever looketh on a woman to lust after her hath committed adultery with her already in his heart.”