A thought experiment developed to counter undue optimism - not just the sort due to explicit theology, but any sense that events and outcomes in our world are more destined, more proportionate, or more meaningful than we have a right to expect.
The thought experiment takes place in a simulated universe such as Conway's Game of Life, but with an overall benevolent God actually *present* to prevent sufficiently awful things from happening. The thought experiment then consists of asking what would happen if we asked the *mathematical* question of what would happen according to the *standard* Life rules given certain initial conditions - so that even God cannot control the answer to the question; although, of course, God always intervenes in the actual Life universe.
The point of the thought experiment is to contrast our intuitions of a supervised universe and an unsupervised universe side-by-side - since the habits of thought associated with a "supervised universe" may carry over past explicit theology.
Example: Would the twentieth century have gone differently, if Klara Pölzl and Alois Hitler had made love one hour earlier, and a different sperm fertilized the egg, on the night that Adolf Hitler was conceived? For so many lives to turn on such a small event seems *disproportionate*, and a supervised universe would be run according to a plan in which things happened for sensible, proportionate reasons; such a small and insensible event would not have such a large influence on the sensible reasons of the plan. It's possible to believe in a divine scheme of things without believing in God (e.g. Karl Marx) but such reasoning belongs to supervised universes rather than unsupervised ones.