Is masturbation unacceptable?
This question has been widely debated because the Scriptures do not directly refer to the practice. However, there are a series of passages that might include it.
"If any man has an emission of semen, then he shall wash all his body in water, and be unclean until evening. And any garment and any leather on which there is semen, it shall be washed with water, and be unclean until evening. Also, when a woman lies with a man, and there is an emission of semen, they shall bathe in water, and be unclean until evening" (Leviticus 15:16-18).
"Whatever man of the descendants of Aaron, who is a leper or has a discharge, shall not eat the holy offerings until he is clean. And whoever touches anything made unclean by a corpse, or a man who has had an emission of semen, or whoever touches any creeping thing by which he would be made unclean, or any person by whom he would become unclean, whatever his uncleanness may be - the person who has touched any such thing shall be unclean until evening, and shall not eat the holy offerings unless he washes his body with water" (Leviticus 22:4-6).
"If there is among you any man who is unclean because of a nocturnal emission, then he must go outside the camp; he may not reenter the camp. But it shall be when evening approaches, he shall bathe himself with water, and at sundown he may reenter the camp" (Deuteronomy 23:10-11).
Just as a woman was considered unclean under the Old Law during her monthly menstruation (Leviticus 15:19-25), a man was considered unclean for one day after he ejaculated. The uncleanness did not mean they had done something wrong or sinful. It was a method of teaching Israel about the nature of sin through physical examples. Breaking God's laws were sinful, but most unclean events were not sinful in and of themselves. For example, a pig is not sinful, but it was unclean and it was sinful to eat pork under the Old Law. Yet today this rule does not exist for Christians (Acts 11:6-9; I Timothy 4:4-5). The uncleanness was by rule and not because of some innate property in the unclean thing. Many of the things called unclean under the Mosaical Law are recognized as reasonable health practices today. A woman's blood flow can be a potential breeding ground for diseases, as can a man's semen.
The rules covered more than semen being released during sexual intercourse. In Leviticus 15:16-18, intercourse is just one way the ejaculation might occur. Deuteronomy 23:10 specifically mentions a second method, a nocturnal emission (or "night wetting"). The male reproductive system constantly produces both sperm and semen. Nocturnal emission is one method God has built into men to handle the problem of excess semen. To put it bluntly, when there is excess semen, the body instinctively pleasures itself to organism to release the excess. Masturbation does produce an emission of semen, so it would be covered by these laws.
Yet, being covered in the laws does not tell us whether masturbation is acceptable to God or not. The laws of uncleanness cover what is to happen after semen was released. For example, adultery would produce an emission of semen; yet, it is clearly condemned (Exodus 20:14). Sexual relations within marriage, however, is approved (Hebrews 13:4). The laws of uncleanness deal with the fact that semen was released, but they do not give us a clue as to whether the method of release is sinful or not. Therefore, if we are going to determine if masturbation is a sin or not, we must approach the problem from a different direction.
Years ago, the story of Onan was cited as evidence that masturbation was sinful.
"Then Judah took a wife for Er his firstborn, and her name was Tamar. But Er, Judah's firstborn, was wicked in the sight of the LORD, and the LORD killed him. And Judah said to Onan, "Go in to your brother's wife and marry her, and raise up an heir to your brother." But Onan knew that the heir would not be his; and it came to pass, when he went in to his brother's wife, that he emitted on the ground, lest he should give an heir to his brother. And the thing which he did displeased the LORD; therefore He killed him also" (Genesis 38:6-10).
The first thing that we must note is that Onan was not masturbating. He was practicing a form of contraception that we commonly call the "withdrawal method." The second thing we need to understand is why God killed Onan. Under ancient common law, if a man died before producing any heirs, his wife was given to the next nearest relative as a wife. The first child produced by this couple would then be considered the child of the dead man with full inheritance rights. Another law that comes into play here is that when a man dies, his estate is divided among his living children. You count the number of children that a man had, add one, and then divide the estate that many ways. The eldest child would receive two portions and the rest would receive one portion each. Judah had three children; hence, Er would have inherited 1/2 of the estate and Onan and his brother would have inherited 1/4 of the estate each. But when Er died, Onan became the eldest child. As such, he would now inherit 2/3 of Judah's estate and his brother would receive 1/3. However, if Onan produced a child for Er with Tamar, that child would receive Er's portion. Onan's inheritance would drop from the current 2/3 of the estate back down to 1/4. This, then, was the motivation for Onan not to get Tamar pregnant and why he was withdrawing before completing the act of sex. Onan's sin was not that his semen was spilled on the ground, but the reason why he took such action. Onan's sin was greed. Hence, the story of Onan does not tell us whether masturbation is right or wrong.
Another approach is to look at the motivation for masturbation. Some men masturbate while looking at pornography. Yet the use of pornography is sin (see the article "At Look at Pornography" for details). Jesus warned, "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). One doesn't have to physically commit a sin to be guilty of the sin. When a person strongly desires to break a law of God, the desire itself is a sin. Therefore, if a person uses thoughts of adultery, fornication, or homosexuality to produce the sexual desire needed to masturbate, that person is committing a sin within his heart even though he has not physically done the deed. Such lust is just as sinful as actually committing the deed.
While we cannot speak as to whether the act of masturbating is a sin or not, we can examine the motivations. Any act of masturbation that is accompanied by thoughts of a sinful act becomes sinful.