The first half of this short epistle acknowledged righteous living. Gaius was one who was walking in truth. He eagerly housed brethren, and as such became a fellow worker for the truth (v. 8). This section presents a stark contrast to the commendable character Gaius displayed.

Diotrephes had the audacity to arrogate any position of authority he could, because he loved the preeminence. He even rejected an apostle of the Lord Jesus Christ! Such arrogance is repulsive.

Additionally, Diotrephes refused to receive brethren into his home as Gaius did, and as others wished to. This lack of desire to dwell in truth and love extended beyond refusal to participate himself. He put others out of the church for participating, and wishing to participate, in the good work.

Such refusal to walk in truth and remain subservient to the doctrine of Christ demands discipline (cf. Titus 3:10). Instead of participating in such nonsense, John encouraged participation in that which is good. He then gave an example of such. Demetrius is one who stood out as a faithful man. Others noticed his good deeds as he walked according to truth. Even John and the other apostles recognized such. Christians are to cling to that which is good, and abhor that which is evil (cf. Romans 12:9).