meaning is simply this: that in the days when our Lord should make his second coming, the sun would be darkened, in the sense that genuine love to the Lord would cease to radiate from the hearts of men; that the moon would not give her light, in the sense that true faith in Him would cease to shine within the souls of men; and that the stars would fall from heaven, in the sense that men's knowledges of spiritual things would fall from their high and heavenly hold upon the human mind, and become earthly, material and debased.
So the fourth day of creation, as the parable relates, was the setting up of the sun, moon and stars, to rule over the day and over the night. And the fourth stage of regeneration is when love to the Lord, faith in the Lord, and knowledges of the Lord's truths, are set up in the spiritual or internal mind to rule the whole realm of heart and mind, affection and thought.
Let us understand this fully. Shall we ask what love is? It is easy to feel what it is, but it is difficult to bring it within the scope of definition. Attachment, preference, liking, fondness, affection, are expressions of somewhat the same meaning, but they do not present the idea of vigor, warmth, depth or intensity which seems to attach to the term love. The word, in all its fullness of meaning, is absolutely without an equivalent in the language.