John urged Gaius to show hospitable love to Demetrius to give Gaius an opportunity to practice love and thereby reprove Diotrephes' lack of love. Demetrius may have carried this letter from John to Gaius,19or he may have visited Gaius later.
John gave three recommendations (witnesses) of this brother's worth. He had a good reputation among all who knew him, his character and conduct were in harmony with the truth, and John personally knew him and vouched for him.
"Like Gaius, Demetrius is walking in the truth.' His life matches his confession. In Pauline terms, he manifests the fruit of the Spirit. In Johannine terms, he lives the life of love."20
It will be interesting to get to heaven and see if this Demetrius is the same man who gave Paul so much trouble in Ephesus (Acts 19:24). Several commentators have concluded that he was.21The odds are against this possibility since there were undoubtedly many men named Demetrius (lit. belonging to Demeter [the goddess of agriculture]) living in that area then. Furthermore Paul ministered in Ephesus in the early 50s whereas John probably wrote this epistle in the early 90s.
