Your question is loaded with assumptions (good ones!) but they should be established first.
- Jesus Christ is revealed in the Old Testament. We know this, because Jesus said so, when he was walking with two men to Emmaus:
25 He said to them, “How foolish you are, and how slow to believe all
that the prophets have spoken! 26 Did not the Messiah have to suffer
these things and then enter his glory?” 27 And beginning with Moses
and all the Prophets, he explained to them what was said in all the
Scriptures concerning himself. (Luke 24:25-27)
- This revelation of Jesus is concealed. This is apparent in the previous words and confusion of the two men in Luke, but also stated here by Paul in Ephesians:
2 Surely you have heard about the administration of God’s grace that
was given to me for you, 3 that is, the mystery made known to me by
revelation, as I have already written briefly. 4 In reading this,
then, you will be able to understand my insight into the mystery of
Christ, 5 which was not made known to people in other generations as
it has now been revealed by the Spirit to God’s holy apostles and
prophets. 6 This mystery is that through the gospel the Gentiles are
heirs together with Israel, members together of one body, and sharers
together in the promise in Christ Jesus.
7 I became a servant of this gospel by the gift of God’s grace given
me through the working of his power. 8 Although I am less than the
least of all the Lord’s people, this grace was given me: to preach to
the Gentiles the boundless riches of Christ, 9 and to make plain to
everyone the administration of this mystery, which for ages past was
kept hidden in God, who created all things. (Ephesians 3:2-7)
- This concealment serves a purpose. Paul lets us know that it is an eternal purpose.
10 His intent was that now, through the church, the manifold wisdom of
God should be made known to the rulers and authorities in the heavenly
realms, 11 according to his eternal purpose that he accomplished in
Christ Jesus our Lord. 12 In him and through faith in him we may
approach God with freedom and confidence. (Ephesians 3:10-12)
- The concealment was intentional and originated in God's actions, not ours.
Thus, continuing with Ephesian 3, though it is true that we are sinners who by our sin blind our hearts to the truth and glory or God, the plan of concealment preceded our sin. We are not the original cause of the concealment; God's plan was.
- Scripture explains some elements of that purpose: the formation of the image of Christ within the believer.
24 Now I rejoice in what I am suffering for you, and I fill up in my
flesh what is still lacking in regard to Christ’s afflictions, for the
sake of his body, which is the church. 25 I have become its servant by
the commission God gave me to present to you the word of God in its
fullness— 26 the mystery that has been kept hidden for ages and
generations, but is now disclosed to the Lord’s people. 27 To them God
has chosen to make known among the Gentiles the glorious riches of
this mystery, which is Christ in you, the hope of glory. (Colossians
- A crucial aspect of God's concealment was that the revelation is the grand work of Israel and the Church:
10 Concerning this salvation, the prophets, who spoke of the grace
that was to come to you, searched intently and with the greatest care,
11 trying to find out the time and circumstances to which the Spirit
of Christ in them was pointing when he predicted the sufferings of the
Messiah and the glories that would follow. 12 It was revealed to them
that they were not serving themselves but you, when they spoke of the
things that have now been told you by those who have preached the
gospel to you by the Holy Spirit sent from heaven. Even angels long to
look into these things. (1 Peter 1:10-12)
If full knowledge of Christ were available before he arrived, the prophets would have nothing to do!
It is the glory of God to conceal a matter;
to search out a matter is the glory of kings. (Proverbs 25:2)
- God's purpose is tied up with the experience of suffering in this world. Ignorance, the seeming purposelessness of life and suffering, these create the ground upon which faith is revealed by its contrast. When the Old Testament believer walked in faith and demonstrated Christ-likeness and Christ-consciousness despite ignorance of who Christ was or what he planned to do, it is a proof of God's power and the ministry of the Holy Spirit:
8 The wind blows wherever it pleases. You hear its sound, but you
cannot tell where it comes from or where it is going. So it is with
everyone born of the Spirit.” (John 3:8)
If you study Job, you will see that in the midst of suffering, ignorance, blindness, and confusion, a man who said he could not see God at the same time spoke words that prophesied the coming savior. In fact, I found nine specific prophesies spoken by Job that point to elements of Jesus' ministry, and those elements are listed in the chronological order in which they occurred in Jesus' life!
Thus the requirement for deep understanding of God's purposes, especially as they relate to the revelation of Jesus, is that a righteous person endure great suffering without abandoning faith in God. There are not many people like that! That is why the greatest revelation had to be performed by Jesus, the perfectly righteous person who suffered the greatest amount. It is only through suffering that the message can be delivered. All the prophets suffered, and from their suffering, faith, and meditation on God's word, they obtained the insight that added to our knowledge of God and the Messiah.
- The message must pass from spoken word through a process of enscripturation in order to come to us in proper context with full assurance of its truth.
Job was likely the first book of the Bible to be written. Prior to Jesus, Job was the most righteous person who ever lived, and he suffered greatly, hence he was a suitable vessel to communicate to us some teaching about Jesus. Job prayed that his words be written down - Job prayed the Bible into existence!
23 “Oh, that my words were recorded,
that they were written on a scroll, 24 that they were inscribed with an iron tool on lead,
or engraved in rock forever! 25 I know that my redeemer lives,
and that in the end he will stand on the earth. 26 And after my skin has been destroyed,
yet in my flesh I will see God; 27 I myself will see him
with my own eyes—I, and not another.
How my heart yearns within me! (Job 19:23-27)