Hi, there. 1st time to use this forum. Pardon the simple-mindedness of the query, but why are the stars appearing at the end so significant? Is it that the cultists had predicted them and thus religion disproves science? Also, if the people are eager for light, wouldn't the stars be welcome? I love Asimov, but for some reason the impact of this story eludes me. Teaching this in a SF course in the fall as a favor to the administration of my school--help!
a) The stars, though legendary and part of their belief system, have never been seen by any generation in millennia; attempts to simulate the stars would be nowhere near as powerful -- imagine never having seen a night sky in your life, and then finding yourself suddenly surrounded by the vault of the night studded with all those lights.
b) The immensity of it all (as mentioned): where with the sunlight -- especially of multiple suns -- things seem a good deal cosier and more "earthbound", once you remove all such light and are left with the genuine physical and emotional impact of the immensity of the universe, something which would completely upset all one's emotional and mental preconceptions (save on the most theoretical level), it would become something overwhelming, even suffocating -- yet at the same time so remote and gigantic that it simultaneously dwarfs not only the individual but the entire species to insignificance. And, again, not on some abstract philosophical level, but at an immediate, down-on-the-bone emotional and instinctual level.
c) It bears something of the same impact as the mythic "seeing the eye of God", and in fact this is something many writers have addressed in different ways: if one suddenly were confronted with the true face of the infinite -- something which we are still very far from even beginning to approach -- then one truly is "looking upon the face of God", and there is simply no way to be emotionally or psychologically prepared for such an experience. It is the supernal experience ne plus ultra, and something human egos simply are not likely to easily withstand.
While the light of the stars would be immense, it would still only emphasize the loneliness of this little planet in the vast void -- hence the fires to "bring back the light", to once again reassert control over their reality (whatever their ostensible reasons for such may be, it is a desperate attempt to reestablish for known in place of the completely unknown which they now face).