My thoughts about false teachers and preachers are correct; if they seek fame and fortune rather than doing the will of God, they speak by their own authority and are not from him.
“If anyone's will is to do God's will, he will know whether the teaching is from God or whether I am speaking on my own authority. The one who speaks on his own authority seeks his own glory; but the one who seeks the glory of him who sent him is true, and in him there is no falsehood.” John 7:17-18
There are many "prophets" that the devil has planted among us. A "true prophet" will probably not identify as such because they do what God called them to do rather than seek fame. Many will be led astray by these so-called prophets; they are liars and will be dealt with by Jesus on judgment day. Choose carefully the teachers whom you listen to and believe. Discernment is crucial; staying immersed in scripture is critical.