Another error that had a widespread influence in the early Church, ranking next to Arianism in importance and even resulting in a considerable portion of the Church splitting off from the main body, was that of Nestorianism. The error of Nestorius was that he carried the dual nature of Christ too far. This gave Christ a double personality, two natures and two persons instead of two natures and one person.
Christ was thus regarded as a man in very close union with God, and Nestorius’ favourite analogy to explain the person of Christ was that of the union of the believer with Christ. This, however, gave us not an incarnate God, but only a deified man,—one who came from below, not from above. Far from giving us a real incarnation, this system gave us only an alliance between God and a man.
Somewhat after the fashion of the Siamese twins, Chang and Eng, God and man were joined together.
We have insisted repeatedly, of course, that Christ is an unique person, that in Him true Deity and true humanity are joined to form one person, and that He is as truly God as is God the Father and as truly man as we are. But we have also pointed out that there is nothing in Scripture to indicate that He was conscious of a double personality. It was not a man but manhood, that is, impersonal generic human nature, that He took into union with Himself. Since He had two natures He also had two wills, the human, however, being always in perfect harmony with and subordinate to the divine.
This latter aspect of His personality was best illustrated in His prayer, “Not my will but thine be done.” We are thus able to distinguish, but not to divide, the two natures in Christ. The chief error of the Nestorian system was that in separating the divine and the human natures in Christ it deprived His human sufferings of the value and efficacy that they must have if they are to be sufficient for the redemption of mankind. As we have pointed out earlier, only when His divine and human nature are organically and indissolubly united in one person can the acts of either nature have the value of both. Hence we are always to insist upon His true Deity, His true humanity, and the unity of His person.