Christian ethics is Christian ethics in so far as it is dogmatic – that is, in so far as it allows its form and content to be shaped by, and tested against, the affirmations of Christian doctrine. More fully we may maintain that Christian ethics is founded upon and arises from the threefold knowledge of God and humankind as creator and creature, reconciler and sinner, redeemer and heir of God's good future, given in the life, death and resurrection of Jesus Christ. Thus it is the task of Christian ethics to understand the claiming of humankind which is implicit within its gracious election as a threefold imperative; specifically Christian ethics may speak of the Gospel of Christ as containing within itself the threefold command of God the creator, the reconciler and the redeemer. As the command of the creator, the command of God commands us to be what we are. As the command of the reconciler, the command of God is directed against the disorder of our present existence. As the command of the redeemer, the command of God directs us to the good future which God intends, and thus to what we shall be.

Christian sexual ethics, to turn to the subject of this chapter, will properly be developed on the basis of this self-understanding, learning, that is to say, to understand and represent life in this sphere as determined by knowledge of the claim made upon us by the grace of God shown in Jesus Christ. It will thus expound three principal theses, displaying Christian sexual ethics as the command of the creator addressed to the creature, as the command of the reconciler addressed to the sinner, and as the command of the redeemer addressed to the heir of God's good future.