'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)

166. (Verse 23) And I will kill her sons with death. That this signifies that thus falsities are extinguished is evident from the signification of sons, as being truths of the church from the Word, and, in the opposite sense, falsities, concerning which we shall speak presently; and from the signification of killing with death, as being to extinguish; for falsities are separated, and, as it were, extinguished by means of temptations, and by man's desisting from them, and fleeing from and holding them in aversion. The reason why sons in the Word signify truths, and, in the opposite sense, falsities is, that, in the spiritual sense of the Word, only those things are treated of that concern the church and heaven; and all things of the church and heaven have reference to the goods of love and the truths of faith. This is why names of consanguinities and affinities, as husband, wife, son, daughter, brother, sister, daughter-in-law, son-in-law, and several others, signify spiritual things that have reference to spiritual birth, which is regeneration, and to the heavenly marriage, which is the marriage of good and truth. The things born from this marriage are also goods and truths; hence it is that by daughters in the Word are signified goods, and by sons, truths, both from good, which is signified by father, and from truth, which is signified by mother. (That all the truths and goods pertaining to the regenerate man, are conjoined according to spiritual affinities, and follow in order, may be seen, Arcana Coelestia 2508, 3815, 4121. That all in heaven are also associated according to spiritual affinities, may be seen in the work, Heaven and Hell 205. That sons signify truths and affections of truth, is shown in Arcana Coelestia, 489, 491, 533, 2623, 3373, 4257, 8649, 9807; that sons' sons signify truths in successive order, n. 6583, 6584; that by father, mother, brethren, children, are signified goods and truths, or evils and falsities, pertaining to man, n. 10490; that to smite the mother upon the sons, denotes to destroy everything belonging to the church, n. 4257; that the Lord called himself the Son of man, because He was Divine truth, and because all the truth of heaven and of the church proceeds from Him, see above, n. 63.)