A.T. Robertson Commentary Revelation 1:5

"and from Jesus Christ, [who is] the faithful witness, the firstborn of the dead, and the ruler of the kings of the earth. Unto him that loveth us, and loosed us from our sins by his blood;" — Revelation 1:5 (ASV)

Who is the faithful witness (ο μαρτυς ο πιστος). "The witness the faithful," nominative in apposition like πρωτοτοκος and αρχων with the preceding ablative Ιησου Χριστου with απο, a habit of John in this book (apparently on purpose) as in 2:13,20; 3:12, etc. See this same phrase in 2:13; 3:14. The use of μαρτυς of Jesus here is probably to the witness (1:1) in this book (22:16f.), not to the witness of Jesus before Pilate (1 Timothy 6:13).

The first-born of the dead (ο πρωτοτοκος των νεκρων). A Jewish Messianic title (Psalms 88:28) and as in Col 1:18 refers to priority in the resurrection to be followed by others. See Lu 2:7 for the word.

The ruler of the kings of the earth (ο αρχων των βασιλεων της γης). Jesus by his resurrection won lordship over the kings of earth (17:14; 19:16), what the devil offered him by surrender (Matthew 4:8f.).

Unto him that loveth us (τω αγαπωντ ημας). Dative of the articular present (not aorist αγαπησαντ) active participle of αγαπαω in a doxology to Christ, the first of many others to God and to Christ (1:6; 4:11; 5:9,12f.; 7:10,12, etc.). For the thought see Joh 3:16.

Loosed (λυσαντ). First aorist active participle of λυω (Aleph A C), though some MSS. (P Q) read λουσαντ (washed), a manifest correction. Note the change of tense. Christ loosed us once for all, but loves us always.

By his blood (εν τω αιματ αυτου). As in 5:9. John here as in the Gospel and Epistles states plainly and repeatedly the place of the blood of Christ in the work of redemption.