The same is true of the concept Son of Man. It is adequate and therefore used, perhaps even by Jesus himself, because it points to the Divine power present in this man to bring the new aeon. On the other hand, it is inadequate because the “son of man” was supposed to appear in power and glory, on the clouds of heaven, (according to Daniel, in symbolic, poetic language.) And so since the inadequacy seems to be greater later on in the pagan world than the adequacy, this term disappeared. Or the term man from above, used by Paul in I Corinthians 15. But Paul sees that this also is difficult. Therefore he says: Now the man from above is historical, and therefore he is the “second man” and not the first; the first is Adam, who fell, and the second is the “man from above,” the Spiritual man, who is identical with Jesus as the Christ. Or they used the term Son of David, which is adequate since he is supposed to be the fulfiller of all the prophecies. But it is inadequate, because David was a king, and “son of David” can indicate a political leader and king. Therefore the fight of Jesus against this misunderstanding, when He says that David himself calls the Messiah his lord.
Then Son of God is adequate because of the special relations and intimate communion between God and Jesus. But it is also inadequate because “son of God” is a very familiar pagan concept. All pagan gods have sons. They propagate sons on earth. Therefore there was a danger in this term, and one added “only begotten, ” and called Him “eternal. ” But it was also difficult for the Jews: they could not stand the pagan connotations. They themselves used that term, but for Israel as the “son of God,” and they couldn’t use it for an individual.