919. 21:23 The city had no need of the sun or of the moon to shine in it, for the glory of God illuminated it, and the Lamb is its lamp. This symbolically means that people of the New Church will not be caught up in self-love and their own intelligence and so possess a natural sight only, but from the Word's Divine truth will possess a spiritual light from the Lord alone.

The sun here symbolizes natural love divorced from spiritual love, which is self-love. And the moon symbolizes a natural intelligence and faith divorced from a spiritual intelligence and faith, which is one's native intelligence and a self-made faith. This is the love and the intelligence and faith symbolized by the sun and moon here, which people of the Lord's New Church will have no need of to light their sight.

The glory of God which illumines the city symbolizes the Word's Divine truth (no. 629), and because that illumination or enlightenment comes from the Lord, we are told as well that the Lamb is its lamp.

The symbolism here is similar to that found in the following verses in Isaiah:

You shall call your walls salvation, and your gates praise. The sun shall no longer be your light by day, nor for brightness shall the moon give light to you; but Jehovah will be to you an everlasting light, and your God your glory. Your sun shall no longer go down, nor shall your moon wane; for Jehovah will be your everlasting light... Your people shall all be righteous. (Isaiah 60:18-21)

The sun and moon that will no longer give light mean self-love and one's native intelligence. And the sun and moon that will no longer go down mean love from the Lord for the Lord, and an intelligence and faith from Him. That Jehovah will be an everlasting light has the same symbolic meaning as what is said here, that the glory of God will illumine the city and the Lamb be its lamp.

That the sun symbolizes love for the Lord, and in an opposite sense self-love, may be seen in nos. 53 and 414 above. And that the moon symbolizes intelligence from the Lord and faith from Him, in nos. 332, 413, 414. Thus the moon in an opposite sense symbolizes one's native intelligence and a self-made faith.

Since the sun in an opposite sense symbolizes self-love, and the moon one's native intelligence and a self-made faith, therefore it was an abomination to worship the sun, moon and stars, as may be seen in Jeremiah 8:1-2.

332. And the sun became as black as sackcloth of hair, and the moon became like blood. This symbolically means that all goodness of love was adulterated in those people, and every truth of faith falsified.

The sun symbolizes the Lord in respect to His Divine love, and thus the goodness of love emanating from Him; and in an opposite sense it symbolizes the Lord's Divinity denied, and thus the goodness of love adulterated. See no. 53 above. And because the sun symbolizes the goodness of love, therefore the moon symbolizes the truth of faith. For the sun has a reddish glow owing to its fire, while the moon glows white from the light radiating from the sun, and fire symbolizes the goodness of love, while light symbolizes the truth arising from that goodness. Regarding the moon, see also the places cited above in no. 53.

The sun is said to have become as black as sackcloth of hair because good adulterated is, in itself, evil, and evil is black.

The moon is said to have become like blood because blood symbolizes Divine truth, and in an opposite sense Divine truth falsified. See nos. 379, 684 below.

The sun and moon are described in almost the same way in Joel:

The sun shall be turned into darkness, and the moon into blood, before the coming of the great and terrible day of Jehovah. (Joel 2:31)