The Infirmity of Reason Versus the Certitude of Faith

Reason is infirm in that it cannot establish anything definitively. It cannot even prove that doubting is the way to truth, "that it is certain that we ought to be in doubt." (Pyrrho entry, Bayle's Dictionary, tr. Popkin, p. 205) But, pace Pierre Bayle, the merely subjective certitude of faith is no solution either! Recoiling from the labyrinth into which unaided human reason loses itself, Bayle writes:

It seems therefore that this unfortunate state [the one brought about by the infirmity of reason] is the most proper one of all for convincing us that our reason is a path that leads us astray since, when it displays itself with the greatest subtlety, it plunges us into such an abyss. The natural conclusion of this ought to be to renounce this guide and to implore the cause of all things to give us a better one. This is a great step toward the Christian religion; for it requires that we look to God for knowledge of what we ought to believe and what we ought to do, and that we enslave our understanding to the obeisance of faith. If a man is convinced that nothing good is to be expected from his philosophical inquiries, he will be more disposed to pray to God to persuade him of the truths that ought to be believed than if he flatters himself that he might succeed by reasoning and disputing. A man is therefore happily disposed toward faith when he knows how defective reason is. (206, emphasis added)

Now how is this a solution to the alleged infirmity of reason? A Christian fideist, acquiescing in pure blind (purblind?) faith, accepts the Trinity while a Muslim fideist, equally subjectively certain of his faith, rejects the Trinity while intoning that God is one. Blind conviction butts up against blind conviction of the opposite kind and all too often strife and bloodshed is the upshot.