The task of Saul is to proclaim Jesus as the Christ before people who have not heard. The focus of his proclamation will be Gentiles and the people of Israel (1 Corinthians 9:19–23). In Acts 25:23–26:29 we read of his proclamation before a king (political ruler).
15 But the Lord said to him, “Go, for he is a chosen instrument of mine to carry my name before the Gentiles and kings and the children of Israel.