Be careful what a prophet tells you", Apostle Abeiku Okai warns.

Words are powerful and for the words spoken by prophets, whether of God or otherwise, there is a kind of force behind due to the fact that in your conscience the person is a 'man of God.'

The Bible is very critical about prophets and prophecies and even warns that we should 'judge prophecies'.  It doesn't say we should judge prophets but their prophecies. So judging prophecy doesn't mean you are judging the vessel. 

If a prophet gives you a prophecy make sure you compare it to what the scriptures say. If his Words are not founded on the truth of the Bible disregard his words or else it might hunt you for life.

If his words doesn't click with your inner man forget it because it can hunt you for life. 

If his words are clearly in violation of what God says about you in respect of the new covenant grace you are under then disregard his words. If not you will lose your ground in the faith.

Prophecies can be positive or negative. It doesn't have to be positive before you know it's of God. For example, 

In Acts 11:10-11 we read, 

"And as we  stayed many days, a certain prophet named  Agabus came down from Judea. When he had  come to us, he took Paul’s belt, bound his own  hands and feet, and said, “Thus says the Holy  Spirit, ‘So shall the Jews at Jerusalem bind the  man who owns this belt, and deliver him into the  hands of the Gentiles.’ ”  

Certainly this wasn't a sweet prophecy and the style of prophesying had no modern intellectual orthodoxy about who a true prophet is. He used signs and even symbolic gestures to communicate his message. But he was right and speaking directly from the Holy Spirit. This same guy had prophesied early about drought in Acts 11:27-28. It seemed all his prophecies were negative but they were all of God.  

But here is the point. Whether a prophecy is positive or negative never accept it without judging it. For the good has the power to mislead you as much as the bad can.

The final word is that let the Bible be your ultimate guide for verification, not your emotions or even perception of the vessel from whom the prophecy comes.

Apostle Abeiku Okai