Here indeed is pure and real religion: faith so joined with an earnest fear of God that this fear also embraces willing reverence, and carries with it such legitimate worship as is prescribed in the law. And we ought to note this fact even more diligently: all men have a vague general veneration for God, but very few really reverence him; and wherever there is great ostentation in ceremonies, sincerity of heart is rare indeed.

John Calvin Institutes, 1.2.2 (HT: Ryan Cavanaugh)