There are three points of doctrine the belief of which forms the foundation of all morality. The first is the existence of God; the second is the immortality of the human soul; and the third is a future state of rewards and punishments. Suppose it possible for a man to disbelieve either of these three articles of faith and that man will have no conscience, he will have no other law than that of the tiger or the shark. The laws of man may bind him in chains or may put him to death, but they never can make him wise, virtuous, or happy.
Abigail Adams, John Quincy Adams, Charles Francis Adams (1848). “Letters of Mrs. Adams: The Wife of John Adams”, p.432, Boston, Wilkins, Carter,