28 And in Antioch also, a most renowned city of Syria, when the preaching of Christ took effect, Barnabas was sent hence as far as Antioch to help on the good work, being a good man, and full of the Holy Ghost, and of faith; who seeing a great harvest of believers in Christ, brought Paul from Tarsus to Antioch, as his fellow-combatant. And when crowds had been instructed by them and assembled in the Church, it came to pass that the disciples were called Christians first in Antioch; the Holy Ghost, methinks, bestowing on the believers that new Name, which had been promised before by the Lord. And the grace of the Spirit being shed forth by God more abundantly in Antioch, there were there prophets and teachers of whom Agabus was one. And as they ministered to the Lord and fasted, the Holy Ghost said, Separate Me Barnabas and Saul for the work whereunto I have called them. And after hands had been laid on them, they were sent forth by the Holy Ghost. Now it is manifest, that the Spirit which speaks and sends, is a living Spirit, subsisting, and operating, as we have said.
Source: Catechetical Lectures (New Advent)