Help me out here, Ex Buddhists.

[Whateverist]

Does believing that the universe is rational and comprehensible give you a nice sense of peace? It isn't.

The world isn't rational or comprehensible. But we can be. That doesn't mean we always reason well or rationally. But I think most of us would rate how well we're doing based on our ability to predict. The amount of peace it provides isn't really the metric most of use to evaluate our world view, though some of us may have fooled ourselves about this.

At least the Buddha taught us:  Believe nothing, no matter who says it, not even if I say it, unless it stands to reason and fits with your common sense.

Well that much is good advice. Is this part where a buddhist would advise us if we meet the buddha on the road, kill him? Don't worry. I don't take that literally.