“Prophesize” and “prophecize” do not exist in current English except as mistakes, although they might become standard if the mistake becomes common enough. In dictionaries that make a fetish of “description, not prescription,” the word “prophesize” may appear without comment, but dictionaries that give usage advice still mark it as incorrect. The Editor’s usual advice applies: use the more correct form in your own writing, but do not treat anyone who uses the other with pedantic contempt.
Having got rid of the obvious mistakes, we are left with two legitimate but easily confused words.
Prophesy is the verb that means to do the work of a prophet—that is, to speak for a deity—or, in common use, to predict the future.
A wonderful and horrible thing is committed in the land; the prophets prophesy falsely, and the priests bear rule by their means; and my people love to have it so. (Jeremiah 5:30-31.)
Analysts prophesy a good year for pork sales.
Prophecy is a noun: a prophecy is what is spoken by a prophet who prophesies, or a prediction of the future spoken by any old yokel.
And when Asa heard these words, and the prophecy of Oded the prophet, he took courage… (2 Chronicles 15:8.)
Clara was not wrong in her prophecy of her father’s decease. Consumption had been long preying upon him, and now he was indeed fast hastening to the grave.
The two words are pronounced differently: prophesy is “PROF-eh-sigh,” and prophecy is “PROF-eh-see.”
“Prophecy” and “prophesy” are often confused, and these are all wrong:
Wrong: Where Isaiah focused much of his prophesy on the doomed northern nation of Israel, Micah placed more of his emphasis on the southern nation of Judah.
Wrong: The Bible says we only see in part when we prophecy.
Wrong: Our prophesy is that the most popular forms of our literature will be written by American women.
Wrong: But aren’t prophets supposed to be 100% right with what they prophecy?
The Editor 