Notes on Biblical teaching on certain sexual activities


A man and a woman are to stand before each other naked on marriage, and no-one else; that is, nudity belongs in marriage only. Indeed the ultimate action of marriage is for both partners standing before each other, un-ashamed, and enjoying each other’s bodies. The Bible commands couples to do so, and do so regularly – sexual intercourse should be frequent, ceasing only for a ‘time’. “Do not deprive one another except with consent for a time, that you may give yourselves to fasting and prayer; and come together again so that Satan does not tempt you because of your lack of self-control” (1 Corinthians 7:5). This is what ‘coming one flesh’ means (Genesis 2:24).

In the beginning nudity had no shame (Genesis 2:25), but it was the sin of Adam that made Adam and Eve ashamed of their nudity, although married to each other. And due to sin this shame has continued ever since. Due to the shame of nakedness (Revelation 3:18 etc.) God provided clothes made from a slain animal to replace their poor attempts of using plant leaves to cover their genitals, at least (Genesis 3:31). Furthermore, the Law sets out steps to prevent the genitals being exposed such as in Exodus 20:26 – noting underwear is a very recent invention. Exposing one’s genitals is considered very shameful outside of marriage. For example Isaiah writes “Your nakedness shall be uncovered, yes, your shame will be seen; I will take vengeance, And I will not arbitrate with a man." (Isaiah 47:3).

The female body is very beautiful, to a man, especially the breasts, about which King Solomon writes in his Proverbs and in great detail in his Song of Songs. For example; “Let your fountain be blessed, and rejoice with the wife of your youth. As a loving deer and a graceful doe, Let her breasts satisfy you at all times; And always be enraptured with her love” (Proverbs 5:18-19). The Bible provides other samples – indeed sexual love is explored by King Solomon in his Song of Songs, which obverses the following about a woman’s breasts; “Your two breasts are like two fawns, twins of a gazelle, that graze among the lilies” (Song of Solomon 4:5). We must however note that in Solomon’s writings nudity is always within marriage, where the context is the love between a man and his wife, a woman (the Bible condemns the notion of same sex marriages). In contrast, nudity, although not forbidden, is not allowed outside the marriage, especially where it may sexually arouse. Arousing someone who is not your spouse causes that person to commit adultery (and is the purpose of pornography). The sin of arousal and lust led to the downfall of King David through his spying on a married woman bathing (2 Samuel 11). Furthermore, the Hebrew euphemism for sexual intercourse is “uncovering her or him” or “exposing his or her nakedness”; meaning the Bible deems undressing and in particular exposing the genitals, a part of the act of sexual intercourse.

In summary, the nude image of a man or woman belongs only to the spouse; and thus only married couples are able to stand before each other naked.

[Note that adultery is fornication where a married person has sex with someone outside the marriage. Fornication in the Old Testament includes pagan idolatry which had sex in their rites. The Bible tends to use the word ‘fornication’ in the Old Testament as a metaphor for gross sin – e.g. “And it shall be, at the end of seventy years, that the LORD will deal with Tyre. She will return to her hire, and commit fornication with all the kingdoms of the world on the face of the earth.” Isaiah 23:17]

Oral sex

Oral sex is not forbidden. Indeed the various forms of arousal and intercourse is not discussed in Scripture, although arousal is described in very graphic and poetic detail in the Song of Solomon. (See note about anal intercourse, below). The Bible is clear, any form of sexual arousal is sex! That is, touching, kissing, partially or totally undressing whether of the genitals or not, is sexual intercourse, if the purpose is to sexually arouse or have sexual intercourse. Oral sex is merely another method of sexual arousal.

One can arouse a partner with one’s foot or hand or hair etc. One does not need to have had a penis placed into a vagina to have had sex (and further to this, ejaculation is not required to call vaginal intercourse ‘sex’ – recognised in our law; for example, rape is less about whether pentation has occurred and more about the intent and harm caused). We can see this from Jesus’s teaching where even thinking about having sex with another person is sexual intercourse. This means a sexually active woman who has had oral sex and has her hymen intact is not a virgin – she has had sexual intercourse. And likewise if a man, who has no external indicators whether he has had virginal sex, unlike a woman, has had oral sex (or any other form - whether to the extent of ejaculation or not), has had sex, and he can no longer call himself a virgin.

“But I [Jesus] say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart”. Matthew 5:28.


Masturbation is not mentioned in the Bible. However, if a person lusts after another woman or man whom they are not married, adultery is committed (Matthew 5:28). Therefore, since the typical way men, at least, become aroused is by fantasying about having sex, or visualising or viewing pictures or videos of nude people, (usually not their spouse), that person is being sexual immoral and sinful, whether or not they masturbate.

Some have attempted to apply Genesis 38, where Onan practiced coitus–interruptus to prevent Tamar from becoming pregnant. However, the sin of Onan is not that he did not ejaculate into Tamar, but because he did not want Tamar becoming pregnant – the text is explicit on this point. The verses cannot be applied to masturbation. The law provided for widows such as Tamar, where an unmarried brother of the late husband of Tamar (he had died) should have taken Tamar as their wife and raised up children, whom would have provided for her – this was the Levirate Law [meaning husband’s brother], which maintained the integrity of the tribe. Onan was right on one account – his reasoning for practicing contraception was because any resulting offspring would not belong to him – they would have legally been Tamar’s, in they would have been considered spiritual sons of the deceased, who would have protected and provided for her (see also Deuteronomy 25). A similar situation arose with Ruth who also became a widow, but in this case a close member of family (next of kin) married her, hence taking the place of her dead husband – providing legal tenure and social security. In this case, the ‘close relative’ Boaz did the right thing and married Ruth. In the case of Onan, the sin was not Onan ejaculating onto the ground, but rather, that fact he did not want to have a child with Tamar (he practiced contraception in “so as not to give offspring to his brother”) and God punished him for this (Genesis 38:9, 10) – thus the passage is uninformative as to God’s view of masturbation.

Other evidence that ejaculating outside of a women’s body is not a sin is that naturally a man’s body will ejaculate every now and again (some have called these wet dreams) if he has not had sexual intercourse, or has not masturbated for some time. This is because the semen becomes old, damaged and less viable – it is God’s way to protect the integrity of the DNA in the chromosomes that will be transmitted from the man to his child. In the same way a woman loses the eggs she produces every month – because the egg cannot last long in the uterus without fertilization – again protecting the integrity of the DNA vital for a sound body.

The sin in masturbation is the ‘lusting’ or ‘fantasying’ after another person other than a spouse which is immoral. Use of pornography to arouse allowing masturbation is a sin, since the purpose of pornography is to arose oneself by another who is not your spouse.


Pornography is a step further than nudity, as explained above, where there is a deliberate attempt to use visual images to sexually arouse, usually by men, but these days, by women as well. Pornography is forbidden as it is adultery. The naked body belongs to the spouse, and no one else. The nude person can be enjoyed, loved, and lifted to extremes of ecstasy, but God allows this to be performed only by the marriage partner.


The Bible does not forbid contraception. Some have applied Genesis 38 to this, because Onan practiced contraception to prevent Tamar, his sister in-law who was a widow from becoming pregnant, contrary to the Levirate law. God punished Onan for failing to impregnate Tamar. However, this situation cannot be applied today, especially to gentiles, since the Levirate law does not apply. God’s anger at Onan’s sin was not because he practiced contraception per se but rather he failed to obey the law that was concerned about providing for Tamar’s wellbeing, having no social security as we have today – which required raising up children by her, in place of her dead husband.

However, God does encourage marriages to produce children. The Lord in Genesis 1:28 said to Adam and Eve, "Be fruitful and multiply and fill the earth and subdue it, and have dominion over the fish of the sea and over the birds of the heavens and over every living thing that moves on the earth."  This command was repeated to Noah in Genesis 9:7 and indeed the blessing to Abraham, given as covenant, was that this seed would become a large people, more than the sands of the sea. Some have interpreted these verses to mean that when the earth of full of people they are to stop having children – and the earth is now full. One argument against the over populated theory to argue against having children is that if humans equitably divided the resources amongst all on this world we would not have starving people in one country and over-fed in another. Therefore, the notion that the world is currently over populated arises from seeing starving people, not because there are too many people. What there is however too many greedy people!

Furthermore, surveys indicate that that economics linked to greed (materialism or the desire to have things including expensive experiences, rather than children) is the principal reason for not having children or only a few, especially in the western world. That is, couples prefer to have a career, own a house, car and take luxurious holidays rather than having children. Therefore, idolatry (coveting is idolatry – Colossians 3:5) is what more often than not that which dissuades couples from not having children, substituting a family for careers and material things.

What we need to remember is that children are a blessing from God – refusing to have children is refusing God’s blessing. This also impacts other members of the family. Proverbs 17:6 states

“Grandchildren are the crown of the aged, and the glory of children is their fathers.”


“Behold, children are a heritage from the LORD, the fruit of the womb a reward. Like arrows in the hand of a warrior are the children of one's youth. They shall not be ashamed, but shall speak with their enemies in the gate.” (Psalms 127:3-5).

Anal intercourse (Sodomy)

The Bible places anal intercourse (also termed sodomy) alongside sexual immorality in the New Testament rather than forbidding it in the Law of the Old Testament. However, it is clear that homosexuality was practiced in Sodom and Gomorrah (Genesis 19:4-5) which God judged severely – God could not find more than ten righteous men in the city (Genesis 18:33) and thus destroyed it. However, it was homosexuality, rather than anal intercourse that was forbidden in the Old Testament Law. In the Old Testament the term “sodomy”, of the type that is described in Genesis, is rape via anal penetration – and all rape is condemned by God; the law demanded death of a man who raped anyone (Deuteronomy 22:25-27). God also condemns homosexuality of any type (Leviticus 18:22; 20:13; Romans 1:26-27; 1 Corinthians 6:9).

Anal sex is a very unnatural act to perform, and indeed Paul uses these very words to describe this activity. Although perhaps permissible between married individuals, from a health point of view it is not recommended. In any case, a man should never place a penis into a woman’s vagina, or mouth, if the penis has been in the anus – it has a very high chance of causing infection.

List of sexual partners forbidden or allowed in the Bible

 “But I say to you that whoever looks at a woman to lust for her has already committed adultery with her in his heart”.  Matthew 5:28

A list of sexual relations forbidden or allowed by God: Biblical Aspects of Sexual Relations (opens new page)

What others have said about homosexuality

Andy Woods, (PhD, Senior Pastor Sugar Land Bible Church, USA)
< > (accessed 1 September 2015) gave two sermons in 2015 in response to the USA Supreme Court's (equivalent to the High Court in Australia) judgement that marriage could occur between two people of the same sex. He is also a lawyer and provides, in layman's terms, the background to the shifting sands of time in the US Supreme court's interpretation of the USA's founding documents, in particular why modern jurists have the notion that the interpretation of the constitution evolves. The sermons can be found at:

Alistair Begg (Senior Pastor, Parkside Church USA)
< > (accessed 1 September 2015) provides a very concise sermon on God's view of homosexuality, using Scripture to underpin the meaning of marriage and God's view of sexual immorality. The sermon can be found at:


David L Simon (December 2014, Updated April 2016, 2017)
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