The Koran and the Bible says to do the same acts of violence to anyone who worships a different God.
Deuteronomy 13:6-8, it reads: "If thy brother, the son of thy mother. Or thy son, or thy daughter, or thy wife of thy bosom. Or thy friend, which is as thine own soul, entice thee secretly, saying, let us go and serve other Gods which thou hast not known, thou, nor thy fathers; (7) namely, of the Gods of the people which are round about you, nigh unto thee, or far off from thee, from the one end of the earth unto the other end of the earth (8) thou shalt not consent unto him, nor harken unto him; neither shalt thou conceal him (9) but thou shalt surely kill him; thine hand shall be first upon him to put him to death, and afterward the hand of all the people. (10) and thou shalt stone him with stones, that he die; because he hath sought to thrust thee away from the Lord thy God, which brought thee out of the land of Egypt, from the house of bondage."
Of course God changed when he became a man called Jesus, he said just turn the other cheek. I guess we must just dump the old testiment as it became outdated.
Ken P.