Buddhism
Buddhism doesn't say ordinary people can't masturbate, although it is prohibited by the Buddha's rules for monks and nuns, who are supposed to live celibate and chaste lives. In general, Buddhist teachers recommend that we keep track of desire, how it comes and goes. Sometimes, they say, not acting on impulse--like the urge to masturbate--we can see how desire falls away if you don't give in to it immediately. Talk about masturbation with other Buddhist teens.
Christian: Catholics
The Catholic Church views masturbation as "an intrinsically and gravely
disordered action." Any sexual act outside of marriage not intended for procreation is considered inappropriate. In 1975, Pope Paul VI outlined why masturbation is wrong in a declaration on human sexuality called Persona Humana. Read all of Persona Humana here.
Christian: Conservative Protestants
Most conservative Christians do not condone masturbation, although masturbation is not explicitly mentioned in the Bible. Christians often conclude that masturbation itself is not a sin, but it is often related to lust, which many Christians believe is sinful. For candid teen talk about masturbation, see this About.com article.
Christian: Liberal Protestants
Most liberal Christians do not find masturbation to be morally offensive, integrating findings of science and research of human sexuality into their beliefs.
As Beliefnet's Pastor Paul says: "I put masturbation in the same category as alcohol. It's a natural act, and one that most people engage in, whether they publicly acknowledge it or not. Done occasionally, it's fine, but when it becomes an obsession or an addiction, it should be stopped, because at that point it alienates us from God."
Earth-Based
Many Pagans and Wiccans view human sexuality as very important and often integrate sexuality into their religious practice. Wiccans and Pagans tend to have a more liberal sexual ethic that many other religions, and therefore are unlikely to condemn masturbation. For more on Neo-Pagan and Wiccan beliefs about masturbation, read this essay from Religioustolerance.org.
Hinduism
According to Hinduism, sexual pleasure is part of kama, one of the four goals of life. On the matter of masturbation, Hindu scripture is silent, neither labeling bad nor encouraging the practice. For more info, check out Himalayan Academy.
Islam
Traditional Islamic thought regards masturbation as haram, or forbidden. This is usually based upon several Qur'an and Hadith verses, which state that people should refrain from illegal sexual acts. A more complete interpretation of these verses can be found here. For a different view, see "Masturbation Is Not Haram." Discuss Islam and masturbation.
Judaism
Rabbis from three different denominations--Conservative, Reconstructionist, and Orthodox--give the Jewish views on masturbation.
Mormon
The Mormon church strongly condemns masturbation and teaches that it is a sin. The church teaches that followers should learn to overcome the impulse to masturbate to retain the sacredness of procreation, and Mormons must control sexual desires until marriage. This Mormon essay, "To Young Men Only," explains how young Mormon men can control their sexual urges.