The fifth theory on this subject is the mystical. This agrees with the moral view (under which it might be included), in that it represents the design of Christ’s work to be the production of a subjective effect in the sinner. It produces a change in him. It overcomes the evil of his nature and restores him to a state of holiness. The two systems differ, however, as to the means by which this inward change is accomplished. According to the one it is by moral power operating according to the laws of mind by the exhibition of truth and the exercise of moral influence. According to the other it is by the mysterious union of God and man, of the divine with the human nature, i.e., of divinity with humanity, brought about by the incarnation.
This general idea is presented in various forms. Sometimes the writers quoted in favour of this mystical view teach nothing more ihan what has ever been held in the Church, and what is clearly caught in the Scriptures.. It is true that there is a moral and spiritual union between God and man effected by the incarnation of the Son of God and the indwelling of the Holy Spirit. He and his people are one. Our Lord prays to the Father, John xvii. 22, 23, that those given to Him “may be one, even as we are one: I in them, and thou in me.” And the Apostle Peter does not hesitate to say that we are made “partakers of the divine nature.” This, and no more than this, is necessarily implied in the oft-quoted language of Athanasius in reference to Christ, αὐτὸς ἐνηνθρώπησεν, ἵνα ἡμεῖς θεοποιηθῶμεν. But besides this Scriptural doctrine there has prevailed a mystical view of the union of God and man to which the redemption of our race is ascribed, and in which, by some of its advocates, it is made exclusively to consist. So far as the fathers are concerned, a clear distinction was made between redemption and reconciliation; between the objective work of Christ in delivering us from the curse of the law and from the power of Satan, and the subjective application of that work. Both were ascribed to Christ. The former (our redemption), was effected by his bearing our sins, by his being made a curse for us, by his giving Himself as a ransom, and by his obedience being taken as a substitute for the obedience which we had failed to render. Our reconciliation with God, including restoration to his image and fellowship, was effected, not, as the Church has ever taught, by the work of the Holy Spirit, but according to the mystical theory, by the union of the divine nature with our fallen nature, brought about by the incarnation. In all ages of the Church there have been minds disinclined to rest in the simple statements of the Bible, and disposed to strive after something more philosophical and profound. Among the early fathers, Münscher says, there was an obscure and peculiar notion that in some way the coming of Christ had produced a physical effect upon our race to ennoble it and render it immortal.1 At times this idea is advanced in general terms and without any attempt to explain philosophically how this effect was produced. As Adam was the cause of the seeds of death and corruption being introduced into human nature, so Christ was the means of introducing a principle of life and immortality which operates as leaven in a mass of dough. Or, as any affection of one member of the body, especially of the head, affects the whole system, so the resurrection of Christ and his life has a physical effect upon the whole mass of mankind. They regarded the human race as one mass which, inasmuch as Christ had united Himself with it by his incarnation, was restored to its original perfection and made immortal.2 This idea was more perfectly worked out by the realists. They held humanity to be a generic substance and life, of which individual men are the modes of existence; and they also held that it was this generic humanity, and not merely a true body and a reasonable soul that Christ assumed into personal union with his divine nature; thus an element of divinity was introduced into humanity, by which it is restored and ennobled, and according to some, finally deified.
Among the Platonizing fathers, however, the mystical operation of the incarnation was connected with their doctrine of the Logos. What the real doctrine of the fathers and of Philo their predecessor and master in his matter concerning the Logos was, has ever been a matter of dispute among the learned. It is not at all even yet a settled matter whether Philo regarded the Logos as a person or not. Dorner, one of the latest and most competent authorities on this point, takes the negative side of the question. According to him Philo taught that the Logos was (1.) A faculty of God, the νοῦς or understanding, and also the power of God. The two are united; thought and power. (2.) The Logos is the activity of God; not merely the power of thought and of creating, but also the actual activity of God in thinking and creating. God first created by thinking an ideal world, after which the actual world was to be fashioned. As a builder forms in his mind the plan of a city in all its details, before he carries that plan into execution; and as the dwelling-place of that ideal city is the understanding of the builder, so the ideal world is in the mind of God, i.e., in the Logos. (3.) According to Philo the Logos is not only the thinking principle which forms this ideal world, but the ideal world itself. (4.) This plenitude of ideas which constitutes the ideal world is the reality, life, and intelligence of the actual world. The latter is (or becomes) by the union of the ideal with matter, what it is. The κόσμος νοητός is realized in the κόσμος αἰσθητός. The Logos, therefore (or the divine intelligence and activity), is the life and intelligence of the actual world. He is the reason in all rational creatures, angels and men.3 According to Philo the Logos was on the one hand identical with God, and on the other identical with the world as its interior reality and life.