Read 3 John 1:12 Using Other Translations
Demetrius hath good report of all men, and of the truth itself: yea, and we also bear record; and ye know that our record is true.
Demetrius has received a good testimony from everyone, and from the truth itself. We also add our testimony, and you know that our testimony is true.
Everyone speaks highly of Demetrius, as does the truth itself. We ourselves can say the same for him, and you know we speak the truth.