I am a simple man who likes simple rules ...
Deuteronomy 18:17-22 [NKJV]
"And the LORD said to me: 'What they have spoken is good. I will raise up for them a Prophet like you from among their brethren, and will put My words in His mouth, and He shall speak to them all that I command Him. And it shall be that whoever will not hear My words, which He speaks in My name, I will require it of him. But the prophet who presumes to speak a word in My name, which I have not commanded him to speak, or who speaks in the name of other gods, that prophet shall die.'"
"And if you say in your heart, 'How shall we know the word which the LORD has not spoken?'-- when a prophet speaks in the name of the LORD, if the thing does not happen or come to pass, that is the thing which the LORD has not spoken; the prophet has spoken it presumptuously; you shall not be afraid of him."
Pentecostal Churches need a pile of cobbles (fist sized rocks) on the raised platform at the front of the church, so a "prophet" can see it and be certain in their mind that God said it, before opening their mouth and saying "Thus says the LORD ..." While we are not under the Old Covenant any longer, uttering a false prophecy should be serious enough that the person is "dead as a prophet" and should not be allowed to speak falsely again.
If I ever believed that God had given me a prophetic word ... (not my gift or passion) ... that is the standard that I would hold myself to.
Let two or three prophets speak, and let the others judge. - 1 Corinthians 14:29 [NKJV]