A missionary should never permit himself to see a movie or (read) cheap literature, or hear music that tends to interfere with or which dampens the spirit of missionary work. There is ample evidence that rock music is offensive to the Spirit and affects adversely the spirituality of the missionaries and thus the success of the proselyting work.
The Teachings of Ezra Taft Benson (ed. Bookcraft Pubs, 1988)
