The faith of the atonement presupposes the faith of the incarnation. It may be also said historically that the faith of the incarnation has usually had conjoined with it the faith of the atonement. The great question which has divided believers as to these fundamental doctrines of the faith has been the relation in which they stand to each other—which was to be regarded as primary, which secondary? Was an atonement the great necessity in reference to man's salvation, out of which the necessity for the incarnation arose, because a divine savior alone could make an adequate atonement for sin? Or, is the incarnation to be regarded as the primary and highest fact in the history of God's relation to man, in the light of which God's interest in man and purpose for man can alone be truly seen? And is the atonement to be contemplated as taking place in order to the fulfillment of the divine purpose for man which the incarnation reveals? These are the questions John McLeod Campbell explores in his influential Nature of the Atonement.
Be sure to check out Classic Studies on the Atonement (32 vols.).