Knowing Them By Their Fruit ...
A prophet is to be proclaiming things heard from God. Whenever God speaks, scripture supports it ... though probably not where someone points, "Thus saith the Lord," stealing God's words (running when He didn't send them).
Prophets guide people through their wilderness. You will know them by their fruit, as God reserves spiritual gifts for those who have the heart for it.
Within the Bible is God's definition for most every word of significance given in scripture. God is His own best commentator. Teachers forgot to teach themselves.
If you are really interested in God's intent, ask Him. Search the scriptures. If you seek God, with your whole heart, He will reveal himself to you. And when His Spirit writes the words upon your heart (which is the truth, as He cannot lie), you will come to 'know' God in newfound ways. The words of His mouth are our necessary food.
Some teach, if you pick just one verse, you are taking it out of context. How, on earth could you have taken it out of context if God spoke it to your heart? However God speaks to your need, that word is infallible. Though, it might be true if you are selecting a verse to support your thinking (telling God what He believes).
Scripture instructs us to compare spiritual things with spiritual things, rightly dividing the words of truth. Deliberately written so the lost would not understand it, you will find the real truths in the hidden parts; as God reveals them to you.
Additionally, when someone speaks in the Spirit, touching your spirit, you can believe God; knowing He dwells within them and you.