The Bible does not specifically condemn masturbation, nor does the Bible specifically condone it. This tends to be one of those "taboo" subjects that people don't often talk about but most Christian Theologians agree that masturbation is for the most part not a sinful act.

Most right-wing Christians will site from Matthew 5:27-28, tht Jesus teaches the spiritual principle that sin begins in the heart, and that the intention to sin is just as bad as committing the sin. Matthew 5:27-28 does not justify the blanket statement that sexual fantasizing is sinful, because that wasn't Jesus' point. Consider the case of a husband who is away from his wife on a business trip. If he looks forward to making love to his wife when he returns, and imagines how nice it will be, this is not a sin - he is building up his desire for his wife and looking forward to being with her again, which helps to enhance their marriage and their relationship. The point is that sexual fantasizing is not a sin since intention to commit a sin is not there.