The Second Epistle of John provides modern readers with a brief but fascinating glimpse into the life of the early Christian Church. Written by a person identifying himself only as "The Elder," it is apparently a letter from one church to another, warning about the heresy known as docetism. This teaching held that Jesus did not come in the flesh. Rather, he was a purely spiritual being who only appeared to have a fleshly body.
From the standpoint of Unification Theology, 2 John is absolutely right to emphasize that Jesus indeed came as a real human being with a fleshly body as well as a spirit, and that those who denied this were in error. However, Unificationism does not entirely agree with the later doctrine of the Incarnation, which taught that Jesus pre-existed as a divine being, the Son, who incarnated as the carpenter of Nazareth. According to the Divine Principle, what pre-existed was not the person Jesus, but the Logos, God's ideal of man and woman, which was originally intended to express itself in Adam and Eve. Because of the Human Fall, Jesus came as the "Second Adam" and indeed incarnated the masculine aspect of the Logos. Because he was crucified before finding his Bride, who would have been a physical woman like Eve, Christ must come again as the Third Adam and form the ideal of True Parents. This, in fact, is the very mission of the Reverend and Mrs. Sun Myung Moon.
Also, although 2 John was correct to criticize the doctrine of docetism, its attitude toward the docetists was harsh and divisive, refusing fellowship to them and even telling those who associated with them that they participated in evil. Ironically, this attitude was quite the opposite of that cited in the same epistle as the basic commandment of Jesus: "that you love one another." By placing doctrine first and unity of heart second, 2 John set an unfortunate precedent for Christian tradition.