As I watched the black cloud overtake my little ocean town that day, I thought all Americans would come together forever. Not exactly spiritual but a strong hope that patriotism would trump everything.
I was quickly disillusioned.
David Hare wrote a beautiful play called “Plenty” about a woman who thinks the horrors of the 2nd World War will bring the world together in peace and love. She, too, is disillusioned.
It may not be to your taste, but the theme of the "Watchmen" graphic novel and (with a slightly modified plot) the movie of the same name, is that humanity would come together and the Cold War would end if everyone were convinced that we all faced imminent destruction from a non-human adversary.
This stuff never works. Not in fiction, not in reality. The takeaway for me is that Human Nature is what it is. We are violent and sinful and we cannot change that. We can try to control ourselves, but we cannot redeem ourselves. That redemption must be given to us, although we cannot earn it and do not deserve it.
Utopia on Earth cannot be achieved, and trying to do so is simply missing the point. It is the great lie which humans have been falling into from the beginning.