The relation between morality and religion has often been discussed. However, it is not always recognized that the relation varies greatly according to the variety of religions. I shall here be concerned solely with Christian theism in its traditional form. I take the latter to signify, essentially, belief in a morally perfect Creator who exists in the threefold form of Father, Son and Holy Spirit and who, in the person of the Son, became man in Christ for our salvation. I thus exclude from consideration all non-theistic accounts of God or the Absolute (such as pantheism or process thought). Also I shall consider, not simply bare theism of the kind that Christians share with Jews and Muslims, but also the distinctively Christian form of theism that is generated by distinctively Christian revelation. Many otherwise sound descriptions of the relation between morality and theism are defective because they fail to consider the distinctively Christian contribution to the theistic concept of God and of his relation to the world.