What does Acts 13:1 mean?

1 Now there were in the church that was at Antioch certain prophets and teachers; as Barnabas, and Simeon that was called Niger, and Lucius of Cyrene, and Manaen, which had been brought up with Herod the tetrarch, and Saul. (Acts 13:1 KJV)

William Burkitt’s Commentary

Observe here, That the city of Antioch being the first Gentile city which entertained the gospel, there were at that time several prophets and teachers in that city to instruct the people, and to lay the foundation of a Christian church amongst them: And amongst others, there was found one very eminent person named Manaen, who was of that high rank and quality, that he was brought up with Herod at court; and, as the learned Lightfoot thinks, was converted there by the preaching of St. John the Baptist: Yet this man, contemning with Moses the pleasures of the court, did think it no disparagement to him to be a teacher at Antioch.

Learn thence, That God is pleased to manifest the freeness of his grace, ineffectually calling some of all sorts and ranks of men, to the knowledge and obedience of the gospel, and to a participation of the benefit offered in and by the Lord Jesus Christ: “Manaen, which had been brought up with Herod the Tetrarch.”