How did the idea that Christ was the Messiah get abroad? Who first knew it and taught it?

God first knew it, and from all eternity. He promulgated the doctrine from the very beginning of the human race, and continuously by the prophets of the Old Testament; Christ taught it clearly as the Gospels prove, and confirmed His claim by miracles; the Apostles and the Catholic Church have promulgated the doctrine throughout the world.

Radio Replies Volume 1 by Rev. Dr. Leslie Rumble MSC and Rev. Charles Mortimer Carty