Gal 3:19,23-24, Rom 10:4, 2 Tim 3:15-16
The Old Testament says that God's law enlightens people's eyes and gives them strength. (Psalm 19:7-9)
Psalms 19:7 The law of the Lord is perfect, converting the soul: the testimony of the Lord is sure, making wise the simple. 8 The statutes of the Lord are right, rejoicing the heart: the commandment of the Lord is pure, enlightening the eyes. 9 The fear of the Lord is clean, enduring for ever: the judgments of the Lord are true and righteous altogether.
The law is the tutor that leads us to Christ. (Gal 3:19,23-24)
Gal 3:19 Wherefore then serveth the law? It was added because of transgressions, till the seed should come to whom the promise was made; and it was ordained by angels in the hand of a mediator. 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.
Christ is the fulfillment of the law. (Romans 10:4)
Romans 10:4 For Christ is the end of the law for righteousness to every one that believeth.
In the Old Testament, there is wisdom in believing that Jesus is the Christ and receiving salvation. (2 Timothy 3:15-16)
2 Timothy 3:15 And that from a child thou hast known the holy scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
16 All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: