Those things in men, which, if they were known to others, would be sufficient to convince others that they are hypocrites, will not convince themselves; and those things which would be sufficient to convince them concerning others, and to cause them to cast others entirely out of their charity, will not be sufficient to convince them concerning themselves. They can make larger allowances for themselves than they can for others. They can find out ways to solve objections against their own hope, when they can find none in the like case for their neighbor.
-- Jonathan Edwards, "Hypocrites Deficient in the Duty of Prayer"