And I always heard it said that nobody ever believed in anything they did not first think was rational. I think it was John Cardinal Newman who said that.
Maybe you cannot noodle out every detail, but nobody just submits to irrationality. Assurance of things not known is not the same as embracing the irrational. It just means you don’t have everything you need for a syllogistic proof. Even the simplest person who is not trained in ordering his thoughts still thinks, and he may not know all the why, but if he is to act upon his beliefs and spread it to others, it must be intelligible.