Religious Messengers
"There are several possible sources of a religious message. The devil may send messages to confuse men. Men may band together and send men who do not know the truth and who preach error. Men may decide within themselves that they are going out with a religious message. Finally, there are those who are chosen by God and sent forth by Him...
"First, the Bible teaches plainly that there are religious messengers who are sent out by the devil. The Lord Jesus Christ flatly told the religious leaders of His day that they were not from the God and Father of the Lord Jesus but that they were sent by Satan. Remember that these words are the words of our Lord Jesus. "I speak of what I have seen with my Father and you do what you have heard from your father...Why do you not understand what I say? It is because you cannot bear to hear my word. You are of your father the devil and your will is to do your father's desire..." (John 8:38-44)...
"In the second place, there are messengers who are sent out by men without the stamp of God's approval. Of these there may be several types. Some will be sent out by children of the devil as in the first instance. But there are others who are sent out by men who are honest, sincere, and even true believers in Christ...The more organizational a church group is, the greater the danger that there will be time servers who enter the ministry or go to the mission field without having been sent by God...
"In the third place, there are men who go out to give a religious message, that may or may not be the Christian message, entirely on their own psychological responsibility without having been sent by God.
"Finally, there are those who are truly sent by God. These latter are marked by the fact that they are faithful to the message of the Gospel, exalting the Lord Jesus Christ, proclaiming to men the good news of salvation through Him, and bidding men to turn from their sins and come to Christ as Saviour and Lord. They back all of their proclamations by the authority of the Bible, the Word of God, and they call Christians to lives of holiness while they themselves are living examples of holiness...
"Unless a man is divinely sent to preach the Word, his ministry will be ineffective to produce faith and life in those to whom he ministers. God must do the sending. I always tell young men who ask me about entering the ministry, that they should never become ministers if they can possibly help it... When God sends a man, there is a yearning, churning, burning inside him. Like Paul he must cry, "For thought I preach the gospel, I have nothing to glory of: for necessity is laid upon me; yea, woe is unto me, if I preach not the gospel" (1 Cor. 9:16)."
Donald Grey Barnhouse, Romans, Vol IV, pages 91-92