Well uhhh... Jesus... duh! OK. Now that we got that out of the way. Let's start with the OT. The word "Christ" doesn't exist in the old testament anywhere. Basically it means "Messiah". The only place the word "messiah" appears in the Bible is Daniel chapter 9. But there are dozens of prophecies of the Messiah in the old testament. Isa 7:14; "Therefore the Lord Himself will give you a sign: Behold, a virgin will be with child and bear a son, and she will call His name Immanuel. There aren't too many virgins that had children. Even in the Bible there is only one woman. This woman will call her son Immanuel. Why is that significant? What does Immanuel mean? Isa 9:6; For a child will be born to us, a son will be given to us; And the government will rest on His shoulders; And His name will be called Wonderful Counselor, Mighty God, Eternal Father, Prince of Peace. There aren't many children in the Bible that are called "Mighty God" either. He is called mighty Father, but the Father wasn't a child born to us. However the Father and the Son are One. The same God. Psa 49:7; No man can by any means redeem his brother Or give to God a ransom for him— Psa 49:8; For the redemption of his soul is costly, And he should cease trying forever— No mere human man can redeem you. No mere man can ransom you or redeem your soul. Psa 49:15; But God will redeem my soul from the power of Sheol, For He will receive me. Selah. But God can. The redeemer could not be a mere human. The Jews of the old testament knew who the Messiah was. They didn't know a lot about Him, but they knew He was God. We could change the word Messiah for Christ here. They knew the Christ was God. There is more from the old testament, but we will start with these for now.