The truth is, that the world, knowing nothing of the blessings of the Catholic faith, and prophesying nothing but ill concerning it, fancies that a convert, after the first fervour is over, feels nothing but disappointment, weariness, and offence in his new religion, and is secretly desirous of retracing his steps. This is at the root of the alarm and irritation which it manifests at hearing that doubts are incompatible with a Catholic's profession, because it is sure that doubts will come upon him, and then how pitiable will be his state! That there can be peace, and joy, and knowledge, and freedom, and spiritual strength in the Church, is a thought far beyond the world's imagination; for it regards her simply as a frightful conspiracy against the happiness of man, seducing her victims by specious professions, and, when they are once hers, caring nothing for the misery which breaks upon them, so that by any means she may detain them in bondage. Accordingly, it conceives we are in perpetual warfare with our own reason, fierce objections ever rising within us, and we forcibly repressing them. It believes that, after the likeness of a vessel which has met with some accident at sea, we are ever baling out the water which rushes in upon us, and have hard work to keep afloat; we just manage to linger on, either by an unnatural strain on our minds, or by turning them away from the subject of religion. The world disbelieves our doctrines itself, and cannot understand our own believing them. It considers them so strange, that it is quite sure, though we will not confess it, that we are haunted day and night with doubts, and tormented with the apprehension of yielding to them. I really do think it is the world's judgment, that one principal part of a confessor's work is the putting down such misgivings in his penitents. It fancies that the reason is ever rebelling, like the flesh; that doubt, like concupiscence, is elicited by every sight and sound, and that temptation insinuates itself in every page of letter-press, and through the very voice of a Protestant polemic. When it sees a Catholic Priest, it looks hard at him, to make out how much there is of folly in his composition, and how much of hypocrisy.
John Henry Newman, Discourses to Mixed Congregations, Discourse 11: Faith and Doubt.