Revelation 1:5

the faithful witness--of the truth concerning Himself and His mission as Prophet, Priest, and King Saviour. "He was the faithful witness, because all things that He heard of the Father He faithfully made known to His disciples. Also, because He taught the way of God in truth, and cared not for man, nor regarded the persons of men. Also, because the truth which He taught in words He confirmed by miracles. Also, because the testimony to Himself on the part of the Father He denied not even in death. Lastly, because He will give true testimony of the works of good and bad at the day of judgment" [RICHARD OF ST. VICTOR in TRENCH]. The nominative in Greek standing in apposition to the genitive, "Jesus Christ," gives majestic prominence to "the faithful witness." the first-begotten of the dead-- (Col 1:18). Lazarus rose, to die again. Christ rose to die no more. The image is not as if the grave was the womb of His resurrection-birth [ALFORD]; but as Act 13:33; Rom 1:4, treat Christ's resurrection as the epoch and event which fulfilled the Scripture, Psa 2:7, "This day (at the resurrection) have I begotten Thee." It was then that His divine Sonship as the God-man was manifested and openly attested by the Father. So our resurrection and our manifested sonship, or generation, are connected. Hence "regeneration" is used of the resurrection-state at the restitution of all things (Mat 19:28). the prince--or Ruler.

— Jamieson-Fausset-Brown Commentary (public domain)