Mingled vanity and pride appear is this, than when miserable men do seek after God, instead of ascending higher than themselves as they ought to do, they measure him by their own carnal stupidity, and neglecting solid inquiry, fly off to indulge their curiosity in vain speculation. Hence, they do not conceive of him in the character in which he is manifested, but imagine him to be whatever their own rashness has devised. This abyss standing open, they cannot move one footstep without rushing headlong to destruction. With such an idea of God, nothing which they may attempt to offer in the way of worship or obedience can have any value in his sight, because it is not him they worship, but, instead of him the dream and figment of their own heart. This corrupt procedure is admirably described by Paul, when he says that “thinking to be wise they became fools” (Rom 1:22).
– John Calvin Institutes of the Christian Religion; Book 1, Chapter 4, Section 1 (Peabody, Ma: Hendrickson 2008), 12.