We have no lack of 'prophets' today. They are everywhere! .. newsstands and libraries; in the news and even in churches. But so often they don't agree and they're wrong. How can you judge them? Judge the prophets with the words of the Bible. "To the law and to the testimony: if they speak not according to this word, it is because there is not light in them." ~Isaiah 8:20 Jesus warned us to be careful of those coming with wonders and predictions. He said in Matthew 24:24, For there shall arise false Christs, and false prophets, and shall shew great signs and wonders; insomuch that, if it were possible, they shall deceive the very elect.
Real prophets receive their call directly from God. Prophets are to speak as given - not adding to nor taking away from for ... every word of God is pure: he is a shield unto them that put their trust in him. Add thou not unto his words, lest he reprove thee, and thou be found a liar. ~Proverbs 30:5-6 The Word of the Lord comes to the prophet. God allows the prophets to see by His spirit and to never compromise.
Prophets exalt God's Word not their own glory. They can say, "Thus saith the Lord! When they do; remember what Jesus told us in Matthew 7:20, Wherefore by their fruits ye shall know them.
You shall know the truth and the truth shall make you free is the life of a prophet as long as God has called them - they are His mouthpiece. Watch for the signs that the prophet has given. Then you can judge them by their very works' sake. Read John 14.