A Christian friend immediately inquired,
Isn't it the other way around? To properly understand Christ we must look through the lens (context) of the "Old Testament", of all that came before him and the environment in which he and his audience lived, worshipped, and understood all of God and life. Especially since he said he didn't come to abolish it?
In answer to his query we turn to scripture.
You search the Scriptures, for in them you think you have eternal life; and these are they which testify of Me. . . . For if you believed Moses, you would believe Me; for he wrote about Me (John 5:39, 46).
And beginning at Moses and all the Prophets, He expounded to them in all the Scriptures the things concerning Himself. . . . Then He said to them, “These are the words which I spoke to you while I was still with you, that all things must be fulfilled which were written in the Law of Moses and the Prophets and the Psalms concerning Me.” And He opened their understanding, that they might comprehend the Scriptures” (Luke 24:27, 44-45).
Notice, Luke says that Jesus “opened their understanding” so that they could “comprehend the Scriptures.” The Old Testament reveals Christ (in types, shadows, sacrifices, prophecies, and promises). If one fails to see this—one misses the central point entirely.
Said another way, the Old Testament cannot be properly understood without reference to Christ. The Old Testament is about Jesus. One can be an “expert” in the Old Testament and not truly understand it, if one does not interpret it in the light of Jesus Christ.
Saint Augustine famously said, “The new is in the old concealed; the old is in the new revealed.” Surely this is true. The Old and New testaments are the interrelated, cumulative revelation of God. But in order to recognize this, one must accept the Person and work of God’s Son.
But their minds were blinded. For until this day the same veil remains unlifted in the reading of the Old Testament, because the veil is taken away in Christ. But even to this day, when Moses is read, a veil lies on their heart. Nevertheless when one turns to the Lord, the veil is taken away (2 Cor. 3:14-16).
In other words, Christ is the key to all scripture.