3 John 1:9 I wrote unto the church: but Diotrephes, who loveth to have the preeminence among them, receiveth us not.
10 Wherefore, if I come, I will remember his deeds which he doeth, prating against us with malicious words: and not content therewith, neither doth he himself receive the brethren, and forbiddeth them that would, and casteth them out of the church.
In these verses John is letting us know that there are people in churches today who are in leadership positions that will not like others telling them what to do. When John did not get a response from a letter he sent to church he knew the leader of that church was full of pride. This person plotted against what was good, malicious words against good people, would not allow a Godly man in his church, and would cast out anyone who was against him. It is good for us to be close enough to God to be able to recognize people like this and not sit under their teaching. As noted here John said he would remember how this person rejected him and the ones who were true followers of Christ. People like this today need us praying for them to see the truth and humble themselves before God.