9 I wrote something to the assembly; but Diotrephes, who loves to have the first place among them, receives us not. 10 For this reason, if I come, I will bring to remembrance his works which he does, babbling against us with wicked words; and not content with these, neither does he himself receive the brethren; and those who would he prevents, and casts [them] out of the assembly.
11 Beloved, do not imitate what is evil, but what is good. He that does good is of God. He that does evil has not seen God.
12 Demetrius has witness borne to him by all, and by the truth itself; and we also bear witness, and thou knowest that our witness is true.
Matthew Henry's Commentary on 3 John 1:9-12
Commentary on 3 John 1:9-12
(Read 3 John 1:9-12)
Both the heart and mouth must be watched. The temper and spirit of Diotrephes was full of pride and ambition. It is bad not to do good ourselves; but it is worse to hinder those who would do good. Those cautions and counsels are most likely to be accepted, which are seasoned with love. Follow that which is good, for he that doeth good, as delighting therein, is born of God. Evil-workers vainly pretend or boast acquaintance with God. Let us not follow that which is proud, selfish, and of bad design, though the example may be given by persons of rank and power; but let us be followers of God, and walk in love, after the example of our Lord.