1Cor 4:6 (Wey) .. in order to teach you by our example what those words mean, which say, "Nothing beyond what is written!"...
The Scripture is strangely silent about this universal issue, while not shy about all sorts of other sexual situations and perversions... in great detail concerning sex with animals, etc. Yet the Bible says nothing about masturbation. This is odd, don't you think?
Some, mistakenly, cite Onan in Gen 38:9 as suggesting that masturbation is a sin. In fact, "onanism" has become a synonym for masturbation. But this is obviously an error, and a rather daft one at that. We know what Onan did, for it is spelled out for us in lurid detail; and we know why it was a sin: he was maliciously using and cheating Tamar in way that was wrong. In any case, what Onan was doing was certainly not masturbating, and you have to be pretty dimwitted to miss this.
In fact, there is no place in scripture where masturbation is even mentioned, much less forbidden. This is a very odd situation since it is so common a human experience, and given that scripture speaks of other sexual sins (some fairly perverse and rare) without any shyness at all.
Since scripture does not forbid masturbation directly, neither should Christians in general. "Nothing beyond what is written" in terms of how we should help lead others to the Lord is the rule. But since you asked, or clicked, as the case may be, we will give you the best answer we can using what we do know from scripture as our guide. We should stick to emphasizing the things God has told us are important, and not be teaching things that the Lord has never expressed His opinion on.
To be sure, it is clear from Scripture that illicit sexual fantasies are forbidden, and this is a significant issue with masturbation.
Matt 5:28-29 (NIV) [Jesus:] "But I tell you that anyone who looks at a woman lustfully has already committed adultery with her in his heart. If your right eye causes you to sin, gouge it out and throw it away. It is better for you to lose one part of your body than for your whole body to be thrown into hell."
But what if no illicit fantasies are included in masturbation? Is the act then sinful? By scripture, there is nothing to indicate that it is. Specifically, if the act is done merely as a hedge against temptation and as the body requires then there is no need for the above sinful "crutches". This is hardly exciting, and a rote act of keeping the body in submission. It cannot be done often, as the body is not that demanding if left alone by a perverted imagination. On the other hand, if we attempt a pent-up self-sex life, then we find that the body needs help from the soul through illicit fantasies, and then sin is clearly being committed.
I hope this is clear. Were it not for our perverted imaginations and lustful sense of expectation, our bodies would not cause us much trouble. It is our minds and hearts that need "treatment". It is like rev-ing an engine near red-line at every traffic signal, and all the time it is running, and then complaining about the eventual engine failure. Sure the thing can rev, but not all the time. It was not made for that.
From Scripture, the line not to be crossed is the line of illicit imagination. And what a line! Minus the sinful fantasies, which are the fuel for most masturbation, all the fun and zest would be taken out of it. Thus, it would no longer be a topic of interest to you or anybody, any more than the act of going to the bathroom. It would be just "doing what was needed" to keep the body from exploding from within.
Sex was not created for this, you can be sure. That God allows masturbation to even work is a mystery (ever try tickling yourself?) and so it is reasonable to assume that it is a "gift" to keep ourselves from temptation.
Eph 5:3 (NIV) But among you there must not be even a hint of sexual immorality, or of any kind of impurity, or of greed, because these are improper for God's holy people.
Much like a person who is an Alcoholic must avoid any kind of drinking like the plague, where others can drink with moderation and without sin, the same principle applies here. So people might come to different conclusions concerning masturbation, and that is anticipated within our faith. Each man must live in holiness before the Lord in his/her own body, and this might mean different disciplines and personal leading in each case. What works for me or you... we should not impose on anybody else as a stumbling block.
Rom 14:12-13 (NIV) So then, each of us will give an account of himself to God. Therefore let us stop passing judgment on one another. Instead, make up your mind not to put any stumbling-block or obstacle in your brother's way.
The important thing is that we live holy before Him, and this is a matter that we should take very seriously. I assume this is why you are interested in this question, because you want to please God by avoiding any kind of sin. And when it comes to sexual sin in the thought-life, in our culture this is an easy temptation to fall into. So care and caution are appropriate as we consider these things and make choices before the Lord.
1Th 4:2-8 (NIV) For you know what instructions we gave you by the authority of the Lord Jesus. It is God's will that you should be sanctified: that you should avoid sexual immorality; that each of you should learn to control his own body in a way that is holy and honorable, not in passionate lust like the heathen, who do not know God... For God did not call us to be impure, but to live a holy life. Therefore, he who rejects this instruction does not reject man but God, who gives you his Holy Spirit.
Can you, in all honesty, masturbate without sinning against the clear commands of Christ? If yes, then we are never told that the act itself is impure or forbidden. But let us be honest and admit that it is not so easy to do if we are committed to avoid mental sexual sin.
In our society, where lust is in the air, how is it is possible to "learn to control our bodies in a way that is holy and honorable"? Well, the answer is that we can die. Really, spiritually. This is The Gospel as we have received it.
John 8:32 (NIV) "Then you will know the truth, and the truth will set you free."
Here is the specific Scripture that set me free, when it finally dawned on me what it meant:
1 Peter 4:1-2 (NIV) Therefore, since Christ suffered in his body, arm yourselves also with the same attitude, because he who has suffered in his body is done with sin. As a result, he does not live the rest of his earthly life for evil human desires, but rather for the will of God.
Think about the radical nature of the spiritual dynamic of what is being explained here. If you are really the recipient of the HOLY Spirit, then this means PAIN in a physical body that lives in this carnal world. If you get this right in your attitude, God says you will be "done with sin". Awesome, eh?
The problem is that we want relief, and sin is the way. But if we agree in advance that the way of the faith must inevitably involve suffering, then we are truly living the gospel and have transferred out of the power of evil and into God's will.
And masturbation, never forbidden by God, can be used as one of the ways that we can "learn to control our bodies"; not by inflaming the body with pornography or fantasies so that it can be done too often, but in using it to keep ourselves from dangerous, physical temptation when it can (rarely) be done without sinning in any way.
Commit yourself to a certain amount of pain, and commit yourself not to sin in thought, and I think you will find that masturbation cannot be done that often, but when it is needed it is a true blessing as a way to keep your body under control. We should not indulge our bodies, but we should "honor" them and learn to live in them properly in this sinful world. For singles, God has given the ability to masturbate, and has not forbidden it. For married couples who are apart and who are thinking of each other, the same applies. But God has most definitely forbidden sinful thoughts that so often accompany masturbation, and for this we all need to die to self and commit ourselves to the fact that living holy in this world will involve pain.
Along these lines, see the Bible Studies on Death to Self, The Cross, and Conviction. Also, you might want to read through the Bible Study on Temptation as well.
I pray that through what we do know, and with the help of the Holy Spirit, that you will be able to conduct yourself in purity and wisdom concerning this matter.
Ro 6:13 (NIV) Do not offer the parts of your body to sin, as instruments of wickedness, but rather offer yourselves to God, as those who have been brought from death to life; and offer the parts of your body to him as instruments of righteousness.
Luke 14:28 (NIV) "Suppose one of you wants to build a tower. Will he not first sit down and estimate the cost to see if he has enough money to complete it? For if he lays the foundation and is not able to finish it, everyone who sees it will ridicule him, saying, 'This fellow began to build and was not able to finish.'"
1 Peter 4:1-2 (Wey) Since, then, Christ suffered in the flesh, you also must arm yourselves with a determination to do the same--because he who has suffered in the flesh has done with sin--that in the future you may spend the rest of your earthly lives, governed not by human passions, but by the will of God.