In the Bible, false prophets fell into 3 categories: (1) those who worshiped false gods and served idols;(2) those who falsely clained to recieve messages from the Lord: (3) those who wandered from the truth and ceased to be true prophets.
A reocurring characteristic of flase prophets is that they often are found in the employment of the powerful and they are careful to speak pleasing, positive and flattering words to their employers. Jeremiah condemned the false prophets who were always saying, "Peace, peace!" when there was no peace (Jer. 6:14; 8:11). The false prophets preached a popular but false message: there would be victory against Babylon (Jer. 28:1-17). Jeremiah said, "The prophets prophesy falsely... and My people love to have it so" ( Jer. 5:31). Even though Jeremiah was a true prophet of the Lord, the false prophets were rewarded by the king and Jeremiah was cast into the dungeon (Jer. 38:6).
-paraphrased Nelson's Bible Dictionary.