'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)

3223. There are two forms of light that give light to man, the light of the world and the light of heaven. The light of the world comes from the sun, the light of heaven from the Lord. The light of the world is intended for the natural or external man, and so for things that exist within the natural man. Although these things do not appear to belong to that light, nevertheless they do, for the natural man is not able to grasp anything except by means of such things as occur and are visible in the world of the natural sun, thus unless they are given some visible form by the light and the shade of that world. All concepts of time and concepts of space, which in the natural man play so great a role that without them he is incapable of thought, belong also to the light of the world. The light of heaven however is intended for the spiritual or internal man. Man's interior mind, where his intellectual concepts reside that are called immaterial, belongs in that light. Of this no one is immediately conscious even though he refers to his intellect as sight and attributes light to it. The reason why he is not immediately conscious of it is that as long as he is engrossed in worldly and bodily interests his perception is solely of such things as belong to the light of the world and not of such as belong to the light of heaven. The light of heaven comes from the Lord alone, and the whole of heaven is bathed in that light.

[2] This light - the light of heaven - is immeasurably more perfect than the light of the world. Things which in the light of the world make a single ray make myriads in the light of heaven. The light of heaven holds intelligence and wisdom within it. This is the light which flows into the light of the world which shines in the external or natural man and causes the latter to perceive things with the senses. Unless the light of heaven were flowing in a person would have no discernment at all, for the life present in things which belong to the light of the world is received from that inflowing light. Between these two forms of light - that is, between things that belong to the light of heaven and those that belong to the light of the world - a correspondence exists when the external or natural man makes one with the internal or spiritual man, that is, when the external man is subservient to the internal. In this case things that occur in the light of the world are representative of such as occur in the light of heaven.