'The first resurrection,' mentioned in Revelation 20:5, 6, does not mean a first resurrection, but the essence and primary part of resurrection, which is salvation and eternal life. There is only one resurrection to life. A second does not happen, and is not mentioned anywhere in the Bible.

(References: Apocalypse Explained 6; Apocalypse Revealed 851; Revelation 20:5-6)

749. And by the word of their testimony.- That this signifies, and, by the confession and acknowledgment of the Divine in His Human, is clear from the signification of the word of testimony, as denoting the confession of the Lord, and the acknowledgment of the Divine in His Human (concerning which see above, n. 392, 635, 649). That this is the word of testimony is plain from the following passages in the Apocalypse:

The angel said unto John, "I am thy fellow-servant, and of thy brethren that have the testimony of Jesus: worship God, for the testimony of Jesus is the spirit of prophecy" (19:10).

And after the angel had thus spoken, a white horse appeared, and one sitting thereon, who was called "the Word of God," also "King of kings and Lord of lords" (verses 13, 16). From this it is evident that the word of their testimony signifies the confession and acknowledgment of the Divine in the Human of the Lord. Those who are in this acknowledgment are also in the acknowledgment that the Human of the Lord is Divine, for the Divine itself cannot dwell elsewhere than in what is Divine from itself. But because the learned among us cannot easily comprehend this, therefore in their thought they separate the Divine from the Human of the Lord, and place the Divine without or above it, nevertheless this is contrary to the Christian doctrine of the trinity, called the Athanasian or Nicene confession, which teaches that the Divine took to itself a Human, and that they are not two but a united Person, just as are soul and body.