Only by himself could he feel himself, only by himself he could tell himself 'I am me'. Before others, among the busy and distracted crowd, he didn’t… - Miguel de Unamuno

To believe in God is to yearn for His existence and, furthermore, it is to act as if He did exist.

Conduct, practice, is the proof of doctrine, theory. "If any man will do His will — the will of Him that sent me," said Jesus, "he shall know of the doctrine, whether it be of God or whether I speak of myself" (John vii. 17); and there is a well known saying of Pascal: "Begin by taking holy water and you will end by becoming a believer." And pursuing a similar train of thought, Johann Jakob Moser, the pietist, was of the opinion that no atheist or naturalist had the right to regard the Christian religion as void of truth so long as he had not put it to the proof by keeping its precepts and commandments (Ritschl, Geschichte des Pietismus, book viii., 43).

...as the great Unitarian preacher Channing pointed out, that in France and Spain there are multitudes who have proceeded from rejecting Popery to absolute atheism, because "the fact is, that false and absurd doctrines, when exposed, have a natural tendency to beget skepticism in those who receive them without reflection. None are so likely to believe too little as those who have begun by believing too much." Here is, indeed, the terrible danger of believing too much. But no! the terrible danger comes from another quarter — from seeking to believe with the reason and not with the life.