I prefer to live in a world where everything is following the same laws all the time, rather than in a world where everything is being guided by an unseen hand that I can't predict or understand. And, throughout history, phenomena that were initially attributed to an inexplicable unseen hand were eventually understood as the sum of forces that act the same way every time (or as a relatively predictable function of some observable initial conditions). I'm not saying the world is deterministic - quantum physics throws that out the window. I'm saying the world is probably understandable.
I don't see any reason to believe that the world/universe is understandable to us, whether or not God is pulling the strings. Even if everything is perfectly rational, does that mean mankind can understand it? A don't think anyone would argue that a dog could "understand" the universe. Humans are certainly smarter than dogs, but are we so smart that everything in the universe will be comprehensible to us?
Is there some "intelligence threshold" beyond which a being is capable of understanding everything that exists, given enough time and data? If there is such a threshold, where is it? Are all humans above it, or only the smartest? Wouldn't it be rather strange for the threshold to randomly fall within the range of normal human intelligence, with some of us above and some below?
Based on some of the stupid people I've known, I think it's fair to say that there are definitely some humans who could not understand everything in the universe under any circumstances. I also know for sure that there are some things that no human yet understands. So, either the threshold is beyond some humans, or it is beyond all humans. I see no evidence to suggest the only former, and the trends tend to prefer the latter. It strikes me as both vain and irrational to believe that oneself is above the threshold and therefore capable of understanding everything.