Thomas Jefferson letter to James Madison, December 16, 1786
Jefferson ranked the importance of his "Bill for Establishing Religious Freedom" equal to the Declaration of Independence. The right of the American people to choose their religion now was on parity with their right to choose their own government.
"The life and essence of religion consists in the internal persuasions or the belief of the mind...external forms of worship, when against our belief, are hypocrisy and impiety. "
The Church should be a "voluntary society," Jefferson asserted. It is "voluntary because no man is by nature bound to any church."
"Is a priest to be our inquisitor, or shall a layman, simple as ourselves, set up his reason as the rule for what we are to read, and what we must believe? It is an insult to our citizens to question whether they are rational beings or not, and blasphemy against religion to suppose it cannot stand the test of truth and reason. "
"Truth will do well enough if left to shift for herself. She seldom has received much aid from the power of great men to whom she is rarely known & seldom welcome. She has no need of force to procure entrance into the minds of men, error indeed has often prevailed by the assistance of power or force."
Source - US Constitution & Bill of Rights Series (Gregory Schaaf, Ph.D.)