Prophecy is a revelation of God's will and designs in relation to man, and the governments of the world.
Prophetic truths are presented in various forms, suited to the varied circumstances and conditions of those addressed.
Prophecy may include doctrine, instruction, warning, entreaty, expostulation, or whatever Yahweh has been pleased to reveal to man.
But specially and principally, prophecy is the foretelling of future events. It is a delineation of the fate of cities, nations, kingdoms, and empires; sometimes with all the minuteness of historic record.
To reveal future events is soley the prerogative of Him who "sees the end from the beginning"; with whom all things are present-nothing past, nothing future.
God accomplishes His purpose through various media. Sometimes he "makes the winds his messengers, and the lightenings his ministers"; the sea hears his voice, and executes his high behests; the earthquake heaves the solid earth, and cities fall; volcanoes belch forth their flames and fiery floods, and consternation and devastation are spread around.
But man is the medium through whom God has been pleased to reveal the purposes of his will; and those through whom he thus communicates are called Prophets.
From The Herald of the Kingdom and Age to Come (1856)