Marriage and Sex Part Two: What Does ‘Sexual Immorality’ Mean?

The Bible uses two different expressions to describe sexual relations outside marriage: ‘adultery’ and ‘sexual immorality’. By ‘adultery’, the Bible means a sexual relationship between a married person and someone who is not their spouse.

There are lots of places in the Bible which tell us what God’s will is in this case. Here are a few of the Bible verses:

Exodus 20:14: You shall not commit adultery.
Matthew 19:18: You shall not commit adultery.
James 2:11: You shall not commit adultery.

So in this regard there is no doubt: we have a clear message from God not to ‘break out’ of our own marriage, or to ‘break into’ another marriage.

The phrase ‘Sexual immorality’

The Bible also speaks clearly about sex between unmarried people. The Bible calls it ‘sexual immorality’. This phrase has a negative and ‘dirty’ ring to it, so a lot of people think this can’t have anything to do with their sexual activity. Therefore it’s important to understand what sexual immorality actually is. The Greek word in the New Testament that is translated as ‘sexual immorality’ is ‘porneia’. This word can also be translated as ‘fornication’.

In a footnote to Matthew 5:27 in one version of the Bible, the phrase ‘sexual immorality’ is explained as ‘all sexual relationships before and outside of marriage’. The meaning of the word doesn’t change whether you have casual sex with someone, or if you sleep with your partner after getting engaged. Both of these actions are sexual immorality, because in both situations the sex act is outside the framework of marriage. The phrase ‘sexual immorality’ occurs over 30 times in the New Testament. Here are some of them:

Matthew 15:19–20: ‘For out of the heart come evil thoughts – murder, adultery, sexual immorality, theft, false testimony, slander. These are what defile a person.’

1 Corinthians 6:18–20: ‘Flee from sexual immorality. All other sins a person commits are outside the body, but whoever sins sexually, sins against their own body. Do you not know that your bodies are temples of the Holy Spirit, who is in you, whom you have received from God? You are not your own; you were bought at a price. Therefore honour God with your bodies.’

1 Corinthians 7:2,9: ‘But since sexual immorality is occurring, each man should have sexual relations with his own wife, and each woman with her own husband … But if they cannot control themselves, they should marry, for it is better to marry than to burn with passion.’

1 Thessalonians 4:3–5 ‘… you should avoid sexual immorality; that each of you should learn to control your own body in a way that is holy and honourable, not in passionate lust like the pagans, who do not know God…’

It’s not about prostitutes

Some people think that sexual immorality is only about sexual relationships with a prostitute. That’s not correct. In the Bible, sexual immorality is having sex with a person you are not married to. This is against the will of God and does not have His blessing.

Here are some Bible verses about love, relationships and sex:

Genesis 39; Proverbs 5–7; Song of Songs;Matthew 19:1–12; 1 Corinthians 6:11–20; Matthew 5:27–32; 1 Corinthians 7:1–9;Ephesians 5:5–6;Ephesians 5:25–33;Hebrews 13:4.

A new start

‘What if I’ve broken God’s commandment not to engage in sexual immorality?’ you might ask. ‘What will I do?’ The answer is simple, but demanding: confess your sin to God, receive His grace and forgiveness, put right your actions and decide to live according to God’s will from now on. It can be hard to break with a lifestyle most Westerners think is totally natural. But taking your faith seriously does come at a price.

At the same time, God wants to give us strength to live the right way, and He wants to give us His joy. And don’t forget the promise: ‘No temptation has overtaken you except what is common to mankind. And God is faithful; He will not let you be tempted beyond what you can bear. But when you are tempted, He will also provide a way out so that you can endure it.’ (1 Corinthians 10:13).

The following Bible verses will help you to see that God’s forgiveness is for you and your situation:

‘“Teacher, this woman was caught in the act of adultery.” … “Then neither do I condemn you,” Jesus declared. “Go now and leave your life of sin”’ (John 8:2–11).

‘If we confess our sins, he is faithful and just and will forgive us our sins and purify us from all unrighteousness’ (1 John 1:9).

‘“Come now, let us settle the matter,” says the Lord. “Though your sins are like scarlet, they shall be as white as snow; though they are red as crimson, they shall be like wool”’ (Isaiah 1:18).

(This is part 2. Click here to read part 1 – ‘What does the Bible say?’)