Is masturbation a sin?

This is a very common question among Christians. Most Christians state that masturbation is a sin, and they point to Genesis 38:8-9 which says “then Judah said to Onan, Lie with your brother's wife and fulfill your duty to her as a brother-in-law to produce offspring for your brother. But Onan knew that the offspring would not be his; so whenever he lay with his brother's wife, he spilled his semen on the ground to keep from producing offspring for his brother. What he did was wicked in the LORD's sight; so he put him to death also.”

Now sadly what most Christians will get from this is “Onan spilled his seed, and this was wicked in the Lord's sight, so the Lord struck him dead. Therefore those who masturbate or spill their seed are worthy of death.” This is greatly taking certain phrases out of context. The story of Onan is that his brother died, and the Lord instructed Onan to sleep with his brother's wife, so that his brother's lineage could continue. While many think that the sin Onan committed was spilling his seed (what most today call masturbation), the true sin if you read the account is that Onan went against what the Lord told him to do. The Lord specifically stated for Onan to sleep with his sister-in-law, but Onan refused blatantly. As a result of his disobedience, he was stricken dead.

It's important also to know that most who say masturbation is wrong say that this is because the man is wasting semen that could become a child. This makes no more sense than those who say God created sex only for pro-creation. Scientifically, the human male produces millions of sperm each day and out of those millions, only a few will ever become children. In that sense, it is no more wasting semen to masturbate than it is to have sex.

Now here's the issue that makes it more complex: the physical act of masturbation is not sinful, but that which is often associated with it is. Allow me to explain. Many times, when someone masturbates, they do so with the aid of something on TV, or a picture, or an audio tape, or mental imagery/fantasies. Usually, this involves lust; the sexual exploitation of another human being, and the carnal desire for them without any respect for them being God's beautiful creation. This is sin. Now most will split hairs and say that you can't have the physical act of masturbation without the thoughts or images to “help it along.” In that case, they are sinning, not based on physical action, but on the basis of lust. For those who say that they can perform the physical action without any such aid, but rather just because the action feels good, they are not sinning.