Who is a Prophet

"if any person should ask me if I were a prophet. I should not deny it, as that would give me the lie; for, according to John, the testimony of Jesus is the spirit of prophesy; therefore, if I profess to be a witness or teacher, and have not the spirit of prophesy, which is the testimony of Jesus, I must be a false witness; but if I be a true teacher and witness, I must possess the spirit of prophesy, and that constitutes a prophet; and any man who says he is a teacher or preacher of righteousness, and denies the spirit of prophecy, is a liar, and the truth is not in him; and by this key false teachers and I posters may be detected." Joseph Smith (HC, 5:215-16)