" Fasting, when practised in prudence, and genuine prayer are conducive to the development of faith with its accompanying power for good. Individual application of this principle may be made with profit. Have you some besetting weakness, some sinful indulgence that you have vainly tried to overcome? Like the malignant demon that Christ rebuked in the boy, your sin may be of a kind that goeth out only through prayer and fasting. "

― James E. Talmage , Jesus the Christ: A Study of the Messiah and His Mission According to Holy Scriptures, Both Ancient and Modern