“Of simple souls, less curious and less learned, are made good Christians, who, through reverence and obedience, believe simply and live under the laws. In the middle range of mental vigor and ability, error in opinion is engendered; those in this range follow the first plausible meaning, and have some claim to regard our sticking to the old ways–those of us who are not versed in these matters by study–as simplicity and stupidity. Great minds, more settled and clear-sighted, make up another type of good believers, who, by long and religious investigation, penetrate to a deeper and more abstruse light on the Scriptures and sense the mysterious and divine secrets of our ecclesiastical polity.”

I.54 “Of vain subtleties” (p.275)

[This is the quote I’ve been looking for, I’m sure, though I think I’d remembered it as being slightly different (focusing, for instance, on faith itself, instead of embodied faith in believers). The version I’d remembered was a little better, I think!]