You may claim the Old Testament Scriptures, but until you actually believe them, you will not recognize your Messiah.

Do not think that I (Jesus) shall accuse you to the Father; there is one who accuses you – Moses, in whom you trust. For if you believed Moses, you would believe me; for he wrote about Me. But if you do not believe his writings, how will you believe my words? John 5:45-47

Abraham believed God and it was counted to him for righteousness. Genesis 15:6