Isa 6:10, Isa 29:10, Rom 11:7-8, 2 Cor 4:4, Rom 10:4, Gal 3:23-25, Lk 24:25-27, 44-45
The Old Testament prophesied that the people of Israel would become dull in their hearts and would not understand the word of God. (Isa 6:10, Isa 29:10)
Isa 6:10 Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they see with their eyes, and hear with their ears, and understand with their heart, and convert, and be healed.
Isa 29:10 For the Lord hath poured out upon you the spirit of deep sleep, and hath closed your eyes: the prophets and your rulers, the seers hath he covered.
Moses wrote the Pentateuch to represent Christ. However, Jews are still looking for Moses when reading the Old Testament. (2 Cor 3:12-18, Rom 11:7-8)
2 Cor 3:12 Seeing then that we have such hope, we use great plainness of speech: 13 And not as Moses, which put a veil over his face, that the children of Israel could not stedfastly look to the end of that which is abolished: 14 But their minds were blinded: for until this day remaineth the same vail untaken away in the reading of the old testament; which vail is done away in Christ. 15 But even unto this day, when Moses is read, the vail is upon their heart. 16 Nevertheless when it shall turn to the Lord, the vail shall be taken away. 17 Now the Lord is that Spirit: and where the Spirit of the Lord is, there is liberty. 18 But we all, with open face beholding as in a glass the glory of the Lord, are changed into the same image from glory to glory, even as by the Spirit of the Lord.
Rom 11:7 What then? Israel hath not obtained that which he seeketh for; but the election hath obtained it, and the rest were blinded. 8 (According as it is written, God hath given them the spirit of slumber, eyes that they should not see, and ears that they should not hear;) unto this day.
The law written by Moses leads us to Christ. (Gal 3:23-25)
Gal 3:23 But before faith came, we were kept under the law, shut up unto the faith which should afterwards be revealed. 24 Wherefore the law was our schoolmaster to bring us unto Christ, that we might be justified by faith. 25 But after that faith is come, we are no longer under a schoolmaster.
The whole Old Testament describes Christ, and that Christ is Jesus. (Lk 24:25-27, 44-45)
Lk 24:25 Then he said unto them, O fools, and slow of heart to believe all that the prophets have spoken:
26 Ought not Christ to have suffered these things, and to enter into his glory?
27 And beginning at Moses and all the prophets, he expounded unto them in all the scriptures the things concerning himself. 44 And he said unto them, These are the words which I spake unto you, while I was yet with you, that all things must be fulfilled, which were written in the law of Moses, and in the prophets, and in the psalms, concerning me. 45 Then opened he their understanding, that they might understand the scriptures,
Satan deceives unbelievers into not realizing that Jesus is the Christ. (2 Cor 4:4)
2 Cor 4:4 In whom the god of this world hath blinded the minds of them which believe not, lest the light of the glorious gospel of Christ, who is the image of God, should shine unto them.