John Calvin on Theistic Atheism

“It is most absurd, therefore, to maintain, as some do, that religion was devised by the cunning and craft of a few individuals, as a means of keeping the body of the people in due subjection, while there was nothing which those very individuals, while teaching others to worship God, less believed than the existence of a God. I readily acknowledge, that designing men have introduced a vast number of fictions into religion, with the view of inspiring the populace with reverence or striking them with terror, and thereby rendering them more obsequious; but they never could have succeeded in this, had the minds of men not been previously imbued with that uniform belief in God, from which, as from its seed, the religious propensity springs. And it is altogether incredible that those who, in the matter of religion, cunningly imposed on their ruder neighbours, were altogether devoid of a knowledge of God. For though in old times there were some, and in the present day not a few are found who deny the being of a God, yet, whether they will or not, they occasionally feel the truth which they are desirous not to know. We do not read of any man who broke out into more unbridled and audacious contempt of the Deity than C. Caligula, and yet none showed greater dread when any indication of divine wrath was manifested. Thus, however unwilling, he shook with terror before the God whom he professedly studied to condemn.”

John Calvin — The Institutes of Christian Religion Book i. Chapter iii. Part ii.