Matthew 5:29-30 have been interpreted differently down through the years. "If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell. And if your right hand causes you to sin, cut it off and throw it away. For it is better that you lose one of your members than that your whole body go into hell." While it should be obvious that Jesus isn't speaking literally here, some have mistaken his words to mean that one way to combat sin is to mutilate the body. In the second century the church Father Origen evidently castrated himself because of these verses.
There are a few reasons why I don't believe Jesus' words are to be taken literally and that to do so actually hurts the cause of holiness. First of all one has to understand the antithetical way Jesus taught. It might also be called hyperbole, but he overstates a point or says it in a radical way to emphasize a point. It is much like stating that one must hate his father or mother in order to follow Christ. Other scriptures define what this "hate" looks like but Jesus makes the point of comparison between love for him and love for everything else. Thus Jesus in our text is pointedly saying that one had better take the battle of sin seriously and do whatever it takes to glorify the Lord.
Another reason that he must have more in mind that holy mutilation is that plucking out one eye still leaves another to lust with and cutting off one hand still leaves another to steal with. To take this literally doesn't solve the problem at all. One might say that what he is getting at is to put out both eyes or cut off both hands. While this might cause some change in one's actions it also fails to achieve what pleases the Lord.
I think Jesus is teaching a principle of sanctification that is more easily seen as one considers all the examples in the Sermon on the Mount. Blinding one's self would on one level aid in the battle with lust. But on another level I believe it would hinder the holiness that Jesus is speaking of in Matthew 5. Christ gave us eyes to serve him. He is most glorified when we can see all that lies around us and love him supremely in spite of the fact that we see these things. Blinding or castrating ourselves removes these opportunities to show to all that we love him more than these things. It says that the Lord isn’t worth the battle to mortify the flesh.
Paul learned to live like that and was able to say that "he had learned to be content in all circumstances". If we blind or castrate ourselves, we have not learned to love Jesus with all our hearts, we have done something akin to suicide. It says that the fight to live for the Lord isn't worth the struggle so I will just quit fighting and do nothing. Perhaps you have controlled your lust to some degree but you haven't demonstrated the surpassing glory of our Savior.
Much better and glorifying to God is that we learn to bring all things under our control because our love for the Lord transcends our love for anything else even the desire for physical pleasure. Our bodies are temples not to be mutilated but to be used for the Lord. It is much more honoring to God that we maintain them in purity than we mar them in a misguided effort not to sin. Besides if we abuse our bodies and still want to sin we haven’t accomplished anything.