Biblical Definition of Adultery

Biblical Definition of Adultery September 7, 2014

How does the Bible define adultery?  Can someone commit adultery and get away with it?

Adultery of the Heart

Jesus was speaking about adultery in several places in the gospels but He also showed that adultery can occur in the heart in Matthew 5:27-30 “You have heard that it was said, ‘You shall not commit adultery.’  But I say to you that everyone who looks at a woman with lustful intent has already committed adultery with her in his heart. If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell.  And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell.”  Since this is true, there is rampant adultery taking place today in the world as pornography is one of the biggest money makers in the world.  To lust after someone in their heart is just like adultery because it occurs in the mind just as the actual physical act.  It is a covetous heart that lusts after the flesh and seeks instant gratification at the expense of another and when we look at another person with lust in our hearts, Jesus is saying that adultery has already been committed but it’s in the heart.   Adultery begins in the heart before it ever reaches the bed so when lust lingers unabated, it conceives sin and that sin, whether the real act or the mental act of adultery, it is still adultery.  Certainly the physical act is far worse but adultery in the heart, by lusting after someone who is not your spouse, is seen as adultery because the mind has performed what the body didn’t have to.

Grounds for Divorce

Jesus gave the grounds for divorce in the same chapter of Matthew 5 saying “It was also said, ‘Whoever divorces his wife, let him give her a certificate of divorce.’ But I say to you that everyone who divorces his wife, except on the ground of sexual immorality, makes her commit adultery, and whoever marries a divorced woman commits adultery” (Matt 5:31-32).  Divorce is permissible when adultery occurs but certainly if someone slips and falls and asks for forgiveness after repentance, the hope is that reconciliation and forgiveness can occur since God hates divorce and striving to save a marriage is a worthwhile effort.  If a person has sex outside of marriage and refuses to repent then their spouse has grounds to divorce them and the offended spouse is not held responsible for the divorce.

What is Adultery?

As Jesus already stated, lusting after someone who is not the person’s spouse is the same thing as adultery but strictly speaking, adultery is having sex with someone who is not your spouse.  If a man is married and has sex with anyone other than his wife, he commits adultery and the same thing goes for the wife if she has sex with someone other than her husband.  Adultery can occur in the heart and in the physical act but actually having sex with someone who is not a spouse is both adultery of the heart and considered sexual immorality.   Adultery has ruined many marriages, has wrecked many homes, and has destroyed millions of children’s faith in marriage and makes the pattern of adultery and divorce more like to occur.  Divorce caused by adultery brings financial ruin too.  It devastates families in multiple ways and no one in the family; children, husband and wife are never the same. It’s true; you cannot unscramble an egg or you cannot take back words once they are spoken.  Adultery does irreparable harm to more than just the immediate family too.  It wreaks havoc on the extended family; parents, in-laws, uncles, aunts, and beyond.  I heard of one employer who would not hire someone who had committed adultery. He reasoned that if they cheated on their wife, what prevents them from cheating in business?

Fornication and Adultery

Fornication is any sex outside of marriage and it also has severe consequences.  When a couple engages in sex before marriage they increase the likelihood of divorce and with this, a higher chance for committing adultery after marriage.  Cleary, the Bible teaches that any sex outside of marriage is sin and since we know we reap what we sow; those who commit pre-marital sex will pay in one way or the other for their sinful lust.  Lusting after someone other than your spouse is either adultery (if done by someone who is married) or sexual immorality (if done outside of marriage). If someone is single and lusts after someone that is married, that is sin to them and God sees it as adultery.

The Sexually Immoral Person’s Destiny

The Bible is crystal clear about what happens to those who commit sexual immorality (adultery or fornication).  Jesus rebuked the Church at Thyatira that allowed sexual immorality to be in the church, “But I have this against you, that you tolerate that woman Jezebel, who calls herself a prophetess and is teaching and seducing my servants to practice sexual immorality and to eat food sacrificed to idols” (Rev 2:20).  Jesus added that “I gave her time to repent, but she refuses to repent of her sexual immorality.  Behold, I will throw her onto a sickbed, and those who commit adultery with her I will throw into great tribulation, unless they repent of her works, and I will strike her children dead” (Rev 2:21-23a).  This shows that Jesus understands that many will commit adultery but then they’ll repent and be forgiven but “unless they repent of her works, and I will strike her children dead.”

Paul stated that “sexual immorality and all impurity or covetousness must not even be named among you, as is proper among saints.  Let there be no filthiness nor foolish talk nor crude joking, which are out of place, but instead let there be thanksgiving. For you may be sure of this, that everyone who is sexually immoral or impure, or who is covetous (that is, an idolater), has no inheritance in the kingdom of Christ and God” (Eph 5:3-5) and “the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions,  envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God” (Gal 5:19-21).  Paul said that “I warned you before” as he did in Ephesians and then again in Galatians.  Those who practice sexual immorality will not be inheriting the kingdom of heaven and this leaves them only one other place to go (Rev 20:11-15).  Adultery and fornication are both considered sexual immorality so the fact is that those who practice such things without repentance, are going to the lake of fire.  John writes in Revelation 21:8 “But as for the cowardly, the faithless, the detestable, as for murderers, the sexually immoral, sorcerers, idolaters, and all liars, their portion will be in the lake that burns with fire and sulfur, which is the second death.”

Biblical Definition of Adultery


If you even think about committing adultery, think about the consequences.  It destroys relationships within marriages and families.  It puts the person at risk for sexually transmitted diseases, it risks an unwanted pregnancy, and above all, it is sin and “those who do such things will not inherit the kingdom of God” (Gal 5:21).  This included adultery, lusting after someone who is not your spouse which is adultery of the heart, and any sex outside of the holy union of marriage.

Another Reading on Patheos to Check Out: What Did Jesus Really Look Like: A Look at the Bible Facts

Article by Jack Wellman

Jack Wellman is Pastor of the Mulvane Brethren church in Mulvane Kansas. Jack is also the Senior Writer at What Christians Want To Know whose mission is to equip, encourage, and energize Christians and to address questions about the believer’s daily walk with God and the Bible. You can follow Jack on Google Plus or check out his book  Blind Chance or Intelligent Design available on Amazon

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