Passage
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.
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.
3 John 1:10 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.
3 John 1:11 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.
3 John 1:12 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.
3 John 1:13 I had many things to write to thee, but I will not with ink and pen write to thee;
3 John 1:14 but I hope soon to see thee, and we will speak mouth to mouth. Peace [be] to thee. The friends greet thee. Greet the friends by name.
The verse centers on "demetrius", "witness", "borne", "truth", "bear", "thou", and "knowest". It is saying that the verse draws attention to "demetrius" and "witness", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 11's "Beloved do not imitate what is evil..." into verse 13's "I had many things to write to...", so "demetrius" and "witness" belong inside that flow. In 3 John context, the local focus is Christ, faith, and discipleship.
A plain takeaway is to answer the verse's own emphasis on "demetrius" and "witness" with trust shaped by these words, not by a vague optimism outside the passage.