There are many that do this and we have threads on this forum about some of those people and we accept them as being sent directly from God as if God put His hand on them. Not going into "name the false prophet" as we would be surprised at how long our list would be. Our list would be spackled with favorite preachers of today. Parts of their teaching may be spot on, but they fail the acid test of God's word in so many areas. Interesting how we classify Nostradamus as a false prophet and yet he was closer with much of his prophecies than the men that speak from the pulpit today.
Consider that they may preach 90% truth and preach 10% deception/lie that directly opposes God's word. Does the Word of God indicate to us to accept them as spokesmen of God or as false prophets after a false prophecy or teaching? How many failed prophecies would it take to determine one is a false prophet?
My stand is to glean as much as I can out of what they say then throw the chaff to the wind, but then I am somewhat seasoned after around 40 years in God's word. For me the red flags go up quickly when men speak things from ignorance that don't pass the Word test. The not so seasoned person could be carried away by the false doctrines or false teaching, and many are. Aren't we responsible for what we feed ourselves and who we allow to feed us?
I heard a lady recently say she had numerous visions from God. She described one of them and clearly it was not a vision from God, but being naive and unlearned in the things of God she was fully sold out to it. There was no way you could tell her that her vision was not from God. You would have been made the fool had you called her out on it.
This is the danger that the unlearned face from what they are taught. They are on a path of ignorance that is hard to reverse. I believe many are sold out to these things and will not force the teachings to go against the measuring line of God's word. I think there is a responsibility that we see in men like Paul, Stephen, and others that we have failed miserably to do.