"The various modes of worship, which prevailed in the Roman world, were all considered by the people, as equally true; by the philosopher, as equally false; and by the magistrate, as equally useful." Chapter 2
"But how shall we excuse the supine inattention of the Pagan and philosophic world to those evidences which were presented by the hand of Omnipotence, not to their reason, but to their senses? During the age of Christ, of his apostles, and their first disciples, the doctrine which they preached was confirmed by innumerable prodigies. The lame walked, the blind saw, the sick were healed, the dead were raised, daemons were expelled, and the laws of Nature were frequently suspended for the benefit of the church. But the sages of Greece and Rome turned aside from the awful spectacle, and, pursuing the ordinary occupations of life and study, appeared unconscious of any alterations in the moral or physical government of the world." Chapter 15
"The philosopher, who with calm suspicion examines the dreams and omens, the miracles and prodigies, of profane or even of ecclesiastical history, will probably conclude that, if the eyes of the spectators have sometimes been deceived by fraud, the understanding of the readers has much more frequently been insulted by fiction. Every event, or appearance, or accident, which seems to deviate from the ordinary course of nature has been rashly ascribed to the immediate action of the Deity and the astonished fancy of the multitude has sometimes given shape and colour, language and motion, to the fleeting but uncommon meteors of the air." Chapter 20
More on the utility of religion may be found here.