Paul Used the Old Testament to Preach Jesus

When Paul addressed the leaders of the Jewish community in Rome, we are informed in the book of Acts:

"When they had appointed a day for him, they came to him at his lodging in greater numbers. From morning till evening he expounded to them, testifying to the kingdom of God and trying to convince them about Jesus both from the Law of Moses and from the Prophets." - Acts 28:23, ESV