Yet the concerns of these two groups should not be ignored, since a greater appreciation of the Old Testament is beneficial in and of itself.
1) To show man’s need of a redeemer. Would anyone question this need after a reading of Exodus, Joshua or Judges? Sin is real and sin is serious. Does something about the Old Testament revolt you? Point made.
3) To show why Redeemer had to come so late in the history of man: enough time to prove that the mechanism of man in time was not self-correcting. History – the time of written record – had now run for nearly two thousand years: in that time no hope had emerged that man could save man, despite the great pagan cultures that had emerged, despite the great pagan religions and philosophies that had emerged over than time.
4) As a corrective for our immanentist tendencies, such as millenarianism, caesaro-papism, and theocratism. Although not a temptation completely removed from history, Christianity has always been awaiting the Kingdom of Heaven, and thus have been much less tempted to impose it in the here-and-now. The Old Testament has also affected Judaism in this manner. The fate of the Kingdom of David is the ultimate warning against immanentism.
5) To reveal the hypostatic union. That Christ is a truly human redeemer, against the docetic tendencies of men, as in Gnosticism and elsewhere.
6) To prove the hypostatic union. The clarity of Isaiah’s prophecies come as close as is possible to breaching the faith barrier.
7) To teach the importance of the hypostatic union. The fact of the Incarnation reveals everything necessary about man. Christ’s human lineage is only important in that it reveals divinity out of sin, that man’s life is meant to be taken up and divinized by God. Christ is not great as Son of David, or as priest of Israel (for, there are many of these in the world still), but Christ is great despite the sins of the sons of David. Divinity is a totally transcendent value, completely unrelated to human pedigree, race or wealth. Although truly a Son of David, the Davidic Kingdom was an insignificant political entity in the greater scale of things.
8) To reveal the oneness of God. We cannot forget the ‘original’ state of man over which the opening scenes of divine revelation was carried out.
9) To reveal something of the mystery of the Blessed Trinity. Monotheism was a lesson slowly enough learned. The truth that God is a trinity of divine persons was that much more difficult to accept. But the truth of the Blessed Trinity is the single most important truth of the universe. It has to be learned. To think otherwise about this ‘reason’ is likely to think that God should not be a trinity.
10) To reveal the true form of moral life, through contrast with the intuitive lex talionis that emerged and continues on in every culture of man. The Law of Love is the way of God, the true law, and no amount of pragmatism can obfuscate this fact. Augustine teaches that first man had to learn not to exceed a just measure in vengeance. Only time (the Old Testament period) and Christ could teach not to take vengeance at all.
The Old Testament might strike one as a lengthy way to make a point: it is a thousand pages long and was composed over the span of a thousand years. One might truly ask, however, whether it is sufficiently long to make its points. At one time or another man has missed all of the above reasons these last two thousand years.