Such wickedness within the church must not be tolerated indefinitely.  It seems likely that Diotrephes was either such a dominating personality that the people were afraid to do anything about him, or else that he had a large enough following that it was impossible to exclude him from the membership without stirring up church strife.  I would rather prefer the former interpretation, based upon what John says in the 10th verse.  The most likely scenario is that Diotrephes was an officer in the church, perhaps an elder, who was abusing his authority due to a lust for power, utterly contrary to the spirit of Christ, Who commanded, “Let him that is greatest among you be your minister.”  Evidently, this was a man who had the ear of the church, and was taking advantage of the platform he had to attack the apostles of Christ.  John says that he was “prating against them with malicious words,” doubtless either undermining their character or their doctrine, or perhaps both.  Thus, we see that it was not Paul alone among the apostles who was attacked by false teachers, but that this was the lot of all the chosen delegates of Christ.

In addition to his malicious attacks upon the apostles, Diotrephes showed a cold, harsh demeanor that was flatly contrary to the doctrine of Christian love which John so consistently promoted.  He refused to receive the brethren, probably counting them as a threat to his own prestige.  We do not know exactly what this rejection of the brethren entailed; perhaps refusing to allow them within the walls of the church, or refusing to receive them into his home with hospitality.  Very likely all this and perhaps more was involved.  But not content with his own cruelty and inhospitableness, he also forbad the other members of the church to receive those sent from John.  It may well be this was the occasion of John writing to Gaius.  Diotrephes the domineering troublemaker was threatening those who received delegates from John with excommunication, but John would stir up his brother in the faith to receive his brethren in the Lord with all graciousness and Christian hospitality in spite of those boisterous threats.

I notice also John’s threat against the proud tyrant Diotrephes, who had gone so far as to cast those out of the church who were receiving their Christian brethren into fellowship.  John says he will remember his deeds.  This he says, not out of a spirit of private revenge, but because Diotrephes was undermining the health of the church, and destroying that Christian charity which is so vital to a healthy body.  John was fully determined that, when he came, he would exercise his apostolic authority to pronounce judgment upon Diotrephes.  Then that evil man would find he himself cast out of the church, and delivered unto Satan, that he no more corrupt the children of God with his evil doctrine and wicked practice.