Berean Standard Bible (BSB)
This is the disciple who testifies to these things and who has written them down. And we know that his testimony is true.
World English Bible (WEB)
This is the disciple who testifies about these things, and wrote these things. We know that his witness is true.
Strong's King James
This{G3778} is{G2076}{(G5748)} the disciple{G3101} which{G3588} testifieth{G3140}{(G5723)} of{G4012} these things{G5130}, and{G2532} wrote{G1125}{(G5660)} these things{G5023}: and{G2532} we know{G1492}{(G5758)} that{G3754} his{G846} testimony{G3141} is{G2076}{(G5748)} true{G227}.
The F.O.G *
(24) This is the disciple who testifies to this and wrote this and know that his testimony is firm-truth.
The F.O.G Message *
Young's Literal Translation
this is the disciple who is testifying concerning these things, and he wrote these things, and we have known that his testimony is true.