“Every new & successful example therefore of a perfect separation between ecclesiastical and civil matters, is of importance. And I have no doubt that every new example, will succeed, as every past one has done, in shewing that religion & Govt. will both exist in greater purity, the less they are mixed together.[Letter to Edward Livingston, 10 July 1822 - Writings 9:100--103]”

“Every new and successful example, therefore, of a perfect separation between the ecclesiastical and civil matters, is of importance; and I have no doubt that every new example will succeed, as every past one has done, in showing that religion and government will both exist in greater purity the less they are mixed together.”

“It may not be easy, in every possible case, to trace the line of separation between the rights of religion and the Civil authority with such distinctness as to avoid collisions and doubts on unessential points. The tendency to usurpation on one side or the other, or to a corrupting coalition or alliance between them, will be best guarded agst. by an entire abstinence of the Govt. from interference in any way whatsoever, beyond the necessity of preserving public order, and protecting each sect agst. trespasses on its legal rights by others.[Letter to the Reverend Jasper Adams, January 1, 1832]”

“Besides the danger of a direct mixture of religion and civil government, there is an evil which ought to be guarded against in the indefinite accumulation of property from the capacity of holding it in perpetuity by ecclesiastical corporations. The establishment of the chaplainship in Congress is a palpable violation of equal rights as well as of Constitutional principles. The danger of silent accumulations and encroachments by ecclesiastical bodies has not sufficiently engaged attention in the U.S.”

“Foreigners have been encouraged to settle among you. Industry and virtue have been promoted by mutual emulation and mutual inspection; commerce and the arts have flourished; and I cannot help attributing those continual exertions of genius which appear among you to the inspiration of liberty, and that love of fame and knowledge which always accompany it. Religious bondage shackles and debilitates the mind, and unfits it for every noble enterprise, every expanded prospect. How far this is the case with Virginia will more clearly appear when the ensuing trial is made.[Letter to William Bradford Jr. April 1 1774]”

“Religious bondage shackles and debilitates the mind and unfitsit for every noble enterprize, every expanded prospect.”

“The purpose of separation of church and state is to keep forever from these shores the ceaseless strife that has soaked the soil of Europe in blood for centuries.[Letter objecting to the use of government land for churches, 1803]”