Acts 5:42, Acts 8:34-35, Acts 17:2-3
In the Old Testament, the scribe Ezra taught the Israelites God's law. (Ezra 7:6,10)
Ezra 7:6 This Ezra went up from Babylon; and he was a ready scribe in the law of Moses, which the Lord God of Israel had given: and the king granted him all his request, according to the hand of the Lord his God upon him. 10 For Ezra had prepared his heart to seek the law of the Lord, and to do it, and to teach in Israel statutes and judgments.
In the early church, those who believed that Jesus was the Christ taught and preached that Jesus was the Christ, whether in the temple or at home. (Acts 5:42)
Acts 5:42 And daily in the temple, and in every house, they ceased not to teach and preach Jesus Christ.
Philip explained the Old Testament to the Ethiopian eunuch and taught that Jesus was the Christ. (Acts 8:34-35)
Acts 8:34 And the eunuch answered Philip, and said, I pray thee, of whom speaketh the prophet this? of himself, or of some other man? 35 Then Philip opened his mouth, and began at the same scripture, and preached unto him Jesus.
Paul opened the Old Testament and proclaimed that Jesus was the Christ. (Acts 17:2-3)
Acts 17:2 And Paul, as his manner was, went in unto them, and three sabbath days reasoned with them out of the scriptures, 3 Opening and alleging, that Christ must needs have suffered, and risen again from the dead; and that this Jesus, whom I preach unto you, is Christ.