[Because the only reason I could see for the characters' behavior was if they literally could not see and hear the world around them. Which brought to mind A Strong Delusion. Note that A Strong Delusion is separate from Left Behind, so this wouldn't be them commenting on Buck, just someone doing Buck like things, for better reason than Buck ever had.]
David and Ana are in an auto dealership.
"I don't understand," David said.
Ana replied, "I wish you would't try." There was a bit of a pause, then, "Don't get me wrong, I don't want you ignorant or anything. It's just that some things don't make sense."
"Yeah... but there's a mushroom cloud over the city."
"They can't see it."
"And the shock-wave that rocked the building?"
"Didn't feel it. The delusion is strong. It has to be. If people realized that 18 months ago every child was kidnapped, this world would have torn itself apart. If they'd noticed while my boss took the reigns of every country-
"Almost," David corrected.
"I don't see what God wants with Israel, he clearly doesn't give a damn about the people there. His prophets are torching them, so why protect it?"
"You're asking me?" David asked. "I'm human."
"Well the point is that it's hard to control a war torn world full of grieving parents. Can you imagine how much harder it would have been to conquer the world from horseback if people knew what was going on?"
""I'm sure Lucifer would have found a way. But this..." David gestured to the dealership, "This goes way beyond a change in leadership. These people are sleeping through World War III."
"I prefer to think of it as the second Rebellion," Ana said. "Some demons felt they could break free of Lucifer and live as happy rulers of the earth. They'll be put down soon."
There was a pause.
"Probably more quickly that God put down the first rebellion," Ana added.
"Leaving us in Nuclear winter."
"I doubt it. No one wants to rule a wasteland. That's part of why there'll be no radiation."
"How will they pull off that?"
"It's called 'magic' for a reason."
David gestured at the people in the dealership, "And none of them will notic- Wait! Did he just negotiate the return of his rental to O'Hare?"
"Sure. Why wouldn't he? It's a lot easier than-"
David pointed at the mushroom cloud out the window, "That O'Hare?"
"David, they can't see it. It's just business as usual for them. I'll be easy enough to get them thinking they dropped the car off with no ill effects. Soon this war will be over and with the exception of a few million dead here and there, there's not going to be much in the way of changes.
"It's just been a while is all. It's been a while since the last time the whole world overlooked something right in front of you. It's been eighteen months and it'll take some time to get used to it."
"Ok. Whatever. About the first Rebellion..."
"Your side had their asses kicked."
"So I've heard."
"What makes them think they can win this time?"