God's Debris

Everything About Fiction You Never Wanted to Know.
Every generation of humans believed it had all the answers it needed, except for a few mysteries they assumed would be solved at any moment. And they all believed their ancestors were simplistic and deluded. What are the odds that you are the first generation of humans who will understand reality?

Scott Adams, creator of Dilbert, presents a "thought experiment". A delivery man brings a package to a crazy old guy. They talk. Then the delivery man becomes an identical crazy old guy. Your mission, according to the introduction, is to find the flaw(s) in the crazy guy's arguments.

It's also available for free online.

Has a sequel, The Religion War, which switches things up by having an actual plot.

Tropes used in God's Debris include:

"I noticed your level is highest. That's obviously the good one. You have to feel glad you're not on one of the other levels."
"No. Happiness comes more easily at the other levels. Awareness has its price. An Avatar can find happiness only in serving."