What is a mystery? By examining the thing closely, I soon perceive, that a mystery is nothing but a contradiction, a palpable absurdity, a manifest impossibility, over which theologians would oblige men humbly to shut their eyes. In a word, a mystery is whatever our spiritual guides cannot explain.

It is profitable to the ministers of religion, that people understand nothing of what they teach. It is impossible to examine what we do not comprehend; when we do not see, we must suffer ourselves to be led. If religion were clear, priests would find less business.

Without mysteries there can be no religion; mystery is essential to it; a religion void of mysteries, would be a contradiction in terms. The God, who serves as the foundation of natural religion, or deism, is himself the greatest of mysteries.