What is the main difference between "Prophecy" and "Prediction"?

The general purpose of prophecy and prediction is the same: to tell what will happen in the future. However, their source of authority for this information is very different. Prophecy relies on the authority of God-given information. True prophecy is therefore never wrong because it always carries the authority of God's truth and character. On the other hand, prediction is based on man's ability to determine what may happen in the future. Prediction is sometimes right but often wrong because it depends on man.

Unfortunately, some who are not prophets claim the gift of prophecy. The Bible teaches that one test of a true prophet is whether or not his prophecy always comes to pass. Deuteronomy 18:22When a prophet speaketh in the name of the LORD, if the thing follow not, nor come to pass, that is the thing which the LORD hath not spoken, but the prophet hath spoken it presumptuously: thou shalt not be afraid of him.
See All... states, "When a prophet speaketh in the name of the LORD, if the thing follow not, nor come to pass, that is the thing which the LORD hath not spoken, but the prophet hath spoken it presumptuously: thou shalt not be afraid of him." People who falsely claim the gift of prophecy are in danger of the judgment of God. It is a serious offense against the Lord.

As to prediction, all men try to do a little of this. However, even in this, we should be careful. Consider this passage from the book of James:

James 4:13Go to now, ye that say, To day or to morrow we will go into such a city, and continue there a year, and buy and sell, and get gain:
See All... Go to now, ye that say, To day or to morrow we will go into such a city, and continue there a year, and buy and sell, and get gain: Whereas ye know not what shall be on the morrow. For what is your life? It is even a vapour, that appeareth for a little time, and then vanisheth away. For that ye ought to say, If the Lord will, we shall live, and do this, or that. But now ye rejoice in your boastings: all such rejoicing is evil. Therefore to him that knoweth to do good, and doeth it not, to him it is sin.

We are not to brag or boast of our knowledge of tomorrow. Things may turn out as we expect, but they may not. We should always speak of the future with humility--"If the Lord will" or "Lord willing." These actions will keep us from the sin of false prophecy and the pride of prediction.