'Preaching' in the Bible

Then I fell down at his feet to worship him, but he [stopped me and] said to me, “You must not do that; I am a fellow servant with you and your brothers and sisters who have and hold the testimony of Jesus. Worship God [alone]. For the testimony of Jesus is the spirit of prophecy [His life and teaching are the heart of prophecy].”

And then I saw thrones, and sitting on them were those to whom judgment [that is, the authority to act as judges] was given. And I saw the souls of those who had been beheaded because of their testimony of Jesus and because of the word of God, and those who had refused to worship the beast or his image, and had not accepted his mark on their forehead and on their hand; and they came to life and reigned with Christ for a thousand years.