Following the Flood, many men, such as Abraham, served as prophets, speaking forth divine revelations. (Ps 105:9, 13-15) However, prior to the establishing of Israel in the Promised Land, regular or vocational preaching does not seem to have been done in a public way. The early patriarchs were under no instructions to act as heralds. During the period of the kingdom rule in Israel, prophets did act as public spokesmen proclaiming God’s decrees, judgments, and summonses in public places. (Isa 58:1; Jer 26:2) Jonah’s proclamation to Nineveh fits well the thought conveyed by keʹryg·ma, and it is so described. (Compare Jon 3:1-4; Mt 12:41.) The prophets’ ministry, however, generally was much broader than that of a herald or preacher, and in some cases they employed others to act as their spokesmen. (2Ki 5:10; 9:1-3; Jer 36:4-6) Some of their messages and visions were written rather than orally proclaimed (Jer 29:1, 30, 31; 30:1, 2; Da chaps 7-12); many were given in private audience, and the prophets also used symbolic acts to convey ideas.​—See PROPHECY; PROPHET.

Though active primarily in the wilderness regions, John the Baptizer did the work of a preacher or public messenger, heralding the approach of the Messiah and God’s Kingdom to the Jews who came out to him and summoning them to repentance. (Mt 3:1-3, 11, 12; Mr 1:1-4; Lu 3:7-9) At the same time John served as a prophet, a teacher (with disciples), and an evangelizer. (Lu 1:76, 77; 3:18; 11:1; Joh 1:35) He was “a representative of God” and His witness.​—Joh 1:6, 7.