The question what to believe is perhaps the most momentous that anyone can put to himself. Our beliefs are not to be classed among the luxuries, but among the necessaries of existence. They become particularly important in times of trouble. They are like the life-boats carried by ocean ships. As long as the sea is smooth and there is every appearance of a prosperous voyage, the passengers seldom take note of the boats or inquire into their sea-worthiness. But when the storm breaks and danger approaches, then the capacity of the boats and their soundness become matters of the first importance.