Most people are familiar with Pascal's wager. Not as many are familiar with its origin. Pascal was the most brilliant mathematician of his day, and some of his advances led to probability calculation improvements, leading to an increase in gambling. As "atonement" for this proliferation of vice, when he became a Christian Pascal playfully applied his probablilty calculations to things of faith. Michael Sugrue jokes about the wager, calling it "Theology for accountants, where the smart money is on God," and Sugrue is right because he's having fun with Pascal. Pascal did not think his wager was a rational proof, it simply demonstrated that respectively one had nothing to lose. It's a playful propaedeutic... a stimulus towards knowledge. Pascal had way too little confidence in reason to think an argument could get anyone to God.
Having designed and built a computer in the 1600's, Pascal could have fit into the Age of Science quite well. But after having a religious experience, he saw Cartesian hubris for what it was, and called it to task. This conversion is what led Nietzsche to declare that
"I will never forgive Christianity for what it did to Pascal."What we can take from that statement is not only that, as you probably already knew, Nietzsche hated Christianity; but that a man as brilliant as Nietzsche saw in a mind as brilliant as Pascal an equal.
With "postmodern" insight centuries before its time, Pascal insists that the Enlightenment's hyper-logical Cartesians were simply making a category mistake. When it came to math and science the philosophes were absolutely right. An appeal to tradition and authority in those arenas didn't do much good (Aristotle had been surpassed). But the category mistake was to then assume that an appeal to tradition and authority was wrong across the board.
For other realms of knowledge such as law or theology, Pascal insists, tradition is a legitmate authority. The proper domain of authority are those things that are inacessible to reason. Centuries later John Henry Newman expressed the same idea when he wrote,
"Liberalism [in religion] then is the mistake of subjecting to human judgment those revealed doctrines which are in their nature beyond and independent of it, and of claiming to determine on intrinsic grounds the truth and value of propositions which rest for their reception simply on the external authority of the Divine Word" (p.219).That quote, well worth reading a second time, expresses Newman's critique of a Christianity that, instead of following the road of Pascal, bought Enlightenment rhetoric and began to try to explain the Christian faith within the domain of what was (then) considered reasonable. Immanuel Kant's "religion within the bounds of reason alone" comes to mind. Newman saw that this approach would ultimately erode the essential nature of the Christian faith, and Newman was right.
Postmodern thinkers today are just now catching up to Pascal and Newman, but nevertheless, I'll give the last word one of them:
"Because he is above the level of the senses and mind, any attempt to evaluate the truth of Christianity within the boundaries of science, philosophy, or history inevitable reduces God to the level of our comprehension. As a result, the God who is accepted or rejected is the God of the philosophers, as Pascal put it, not the God of Abraham, Isaac, and Jacob. This is often misunderstood by both those inside and outside the Church. For example, everyone agrees that we must have faith. But this is understood to mean that faith in necessary only because we do not have enough evidence to affirm the reality of God. That this is a mistaken understanding of faith is clear, for it implies that should we ever get enough evidence, faith would be unnecessary. But faith properly understood is, on the contrary, a response to a revelation of God, the revelation of a reality which is above reason. Faith in what is above reason is possible only because of some action within us by God. Faith is thus not a substitute for evidence but a response to God makde possible by him (p. 135-36).