Now Judas and Silas, themselves being prophets also, exhorted and strengthened the brethren with many words.
In Acts 15:32, we see that two prophets exhorted and strengthened the brethren with many words. And now we see why God doesn't just hand out the gift of prophecy lightly. Christians won't listen for long to incompetent speakers or to Christians with a bad testimony. A person who lacks knowledge, can't teach, uses the wrong words, or does not command respect can't perform a prophet's duties.
We're told to seek the better gifts, especially that we may prophesy. If you obey this command, you might find God working in your life before He gives you what you ask for.