What is the difference between fornication and adultery?

The modern dictionary definitions of fornication (voluntary sexual intercourse between persons not married to each other, which would include adultery) and adultery (voluntary sexual intercourse between a married person and a partner other than the lawful spouse) are simple enough, but the Bible gives us greater insight into how God perceives these two sexual sins. In the Bible, both are referred to literally, but both are also used figuratively to refer to idolatry.

In the Old Testament, all sexual sin was forbidden by the Mosaic Law and Jewish custom. However, the Hebrew word translated “fornication” in the Old Testament was also in the context of idolatry, also called spiritual whoredom. In 2 Chronicles 21:10-14, God struck Jehoram with plagues and diseases because he led the people into idolatry. He “caused the people of Jerusalem to commit fornication” (v. 11, KJV) and “to go lusting like the fornications of the house of Ahab” (v. 13 NKJV). King Ahab was the husband of Jezebel, a priestess of the lascivious god Baal, who led the Israelites into idol worship of the most egregious kind. In Ezekiel 16, the prophet Ezekiel describes in detail the history of God’s people turning away from Him to “play the harlot” with other gods. The word “fornication,” meaning idolatry, is used numerous times in this chapter alone. As the Israelites became known among the nations round about them for their wisdom, riches, and power, which was a snare to them as a woman’s beauty is to her, they were admired and courted and complimented by their neighbors, and so drawn into idolatrous practices. The word “fornication” is used in connection with pagan idolatry because much of pagan “worship” included sex in their rites. Temple prostitutes were common in the worship of Baal and other false gods. Sexual sin of all kinds was not only accepted in these religions, but encouraged as a means to greater blessings from the gods for the worshippers, particularly in the increase of their flocks and crops.

In the New Testament, “fornication” comes from the Greek word porneia, which includes adultery and incest. Porneia comes from another Greek word that also includes indulging in any kind of unlawful lust, which would include homosexuality. The use of the word in the gospels and the epistles is always in reference to sexual sin, whereas “fornication” in the book of Revelation always refers to idolatry. The Lord Jesus condemns two of the churches of Asia Minor for dabbling in the fornication of idolatry (Revelation 2:14, 20), and He also refers to the “great harlot” of the end times, which is the idolatrous false religion “with whom the kings of the earth committed fornication, and the inhabitants of the earth were made drunk with the wine of her fornication” (Revelation 17:1-2, NKJV).

Adultery, on the other hand, always refers to the sexual sin of married people with someone other than their spouse, and the word is used in the Old Testament both literally and figuratively. The Hebrew word translated “adultery” means literally “breaking wedlock.” Interestingly, God describes the desertion of His people to other gods as adultery. The Jewish people were regarded as the spouse of Jehovah, so when they turned to the gods of other nations, they were compared to an adulterous wife. The Old Testament often referred to Israel’s idolatry as a wanton woman who went “whoring after” other gods (Exodus 34:15-16; Leviticus 17:7; Ezekiel 6:9 KJV). Further, the entire book of Hosea likens the relationship between God and Israel to the marriage of the prophet Hosea and his adulterous wife, Gomer. Their marriage was a picture of the sin and unfaithfulness of Israel which, time after time, left her true husband (Jehovah) to commit spiritual adultery with other gods.

In the New Testament, the two Greek words translated “adultery” are nearly always used, from their contexts, to refer literally to sexual sin involving married partners. The only exception is in the letter to the church of Thyatira which was condemned for tolerating the “woman Jezebel who calls herself a prophetess” (Revelation 2:20). This woman drew the church into immorality and idolatrous practices and anyone seduced by her false doctrines was considered to have committed adultery with her.

Premarital sex – why are Christians so strongly against it?

Premarital sex involves any kind of sexual contact prior to entering into a legal marriage relationship. There are a number of reasons why Scripture and traditional Christianity oppose this. God designed sex to be enjoyed within a committed marital relationship. To remove it from that context is to pervert its use and severely limit its enjoyment. Sexual contact involves a level of intimacy not experienced in any other human relationship. When God brought Adam and Eve together in marriage, He established the “one flesh” relationship. Genesis 2:24 tells us that a man will leave his family, join to his wife, and become “one flesh” with her.

This idea is carried through in the New Testament as well; we see it in Jesus’ words in both Matthew 19:5 and Mark 10:7. Paul elaborates on that idea in 1 Corinthians 6:12-20, in his discussion of God’s lordship over our bodies as well as our souls. He says that when a man has sex with a prostitute, they have become “one body” (verse 16). It’s clear that the sexual relationship, no matter the context, is special. There is a level of vulnerability one experiences in a sexual relationship which should only occur within a committed, trusting, marital union.

There are, in general, two contexts for premarital sex. There is the “we love each other and are committed to each other, but just don’t want to wait to be married” sexual relationship, and there’s “casual sex.” The former is often rationalized with the idea that the couple will surely marry, so there’s no sin in engaging in marital relations now. However, this shows impatience and disrespect to oneself, as well as the other person. It removes the special nature of the relationship from its proper framework, which will erode the idea that there’s a framework at all. If we accept this behavior, it’s not long before we’ll regard any extra-marital sex as acceptable. To tell our prospective mate that they’re worth waiting for strengthens the relationship and increases the commitment level.

Casual sex is rampant in many societies. There is, in truth, no such thing as “casual” sex, because of the depth of intimacy involved in the sexual relationship. An analogy is instructive here. If we take a sticky note and attach it to a piece of paper, it will adhere. If we remove it, it will leave behind a small amount of residue; the longer it remains, the more residue is left. If we take that note and stick it to several places repeatedly, it will leave residue everywhere we stick it, and it will eventually lose its ability to adhere to anything. This is much like what happens to us when we engage in “casual” sex. Each time we leave a sexual relationship, we leave a part of ourselves behind. The longer the relationship has gone on, the more we leave behind, and the more we lose of ourselves. As we go from partner to partner, we continue to lose a tiny bit of ourselves each time, and eventually we may lose our ability to form a lasting sexual relationship at all. The sexual relationship is so strong and so intimate that we cannot enter into it casually, no matter how easy it might seem.

So, is there hope? When a Christian engages in premarital sex, or when one who has lost his/her virginity comes to Christ, the Holy Spirit will convict of the sin, and there will be grief over it. However, it’s important – even vital – to remember that there is no sin beyond the reach of the blood of Jesus. If we confess, He will not only forgive, but will cleanse us from “all unrighteousness” (1 John 1:9). Furthermore, in addition to the forgiveness (which is in itself glorious), God restores. Joel 2:25 tells us that God is able to restore the years that the locust has eaten, and that’s what premarital sex is—a locust that consumes our sense of self, our self-esteem, and our perception of forgiveness. Scripture also tells us that when we come to Christ, we are new creations (2 Corinthians 5:17), so one who engaged in premarital sex prior to conversion is recreated by God into a new person; the old is gone, the new has come.

Finally, we know that, as Christians, we’re being renewed by the Holy Spirit each day we walk with Jesus. Colossians 3:10 tells us that our new self is being renewed day by day after the image of its Creator. There is no sin without hope. The power of the gospel is available to all who trust in Jesus for forgiveness.