Note 12 at Ac 2:25: Peter, under the inspiration of the Holy Spirit, began to quote from Old Testament scriptures to prove to the people that Jesus was indeed the Messiah. All the things that had happened to Him were prophesied hundreds of years before.

Just as Peter used fulfillment of prophecy to prove Jesus was the Christ, so one of our strongest arguments as to the truth of who Jesus is, is the way He so perfectly fulfilled prophecy (see note 1 at Mt 26:24).