Religious bondage shackles and debilitates the mind and unfits it for every noble enterprise.... During almost fifteen centuries has the legal establishment of Christianity been on trial. What have been its fruits? More or less, in all places, pride and indolence in the clergy; ignorance and servility in laity; in both, superstition, bigotry, and persecution.

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]

Religious bondage shackles and debilitates the mind, and unfits it for every noble enterprise, every expanded prospect.[Letter to William Bradford Jr. April 1 1774]

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.

... [E]xperience witnesseth that ecclesiastical establishments, instead of maintaining the purity and efficacy of Religion, have had a contrary operation. During almost fifteen centuries has the legal establishment of Christianity been on trial. What have been its fruits? More or less in all places, pride and indolence in the Clergy, ignorance and servility in the laity, in both, superstition, bigotry and persecution.

The civil government ... functions with complete success ... by the total separation of the Church from the State.

[Christianity] existed and flourishes, not only without the support of human laws, but in spite of every opposition from them.

[The human mind] finds more facility in assenting to the self-existence of an invisible cause possessing infinite power, wisdom, and goodness, than in the self-existence of the universe, visibly destitute of these attributes, and which may be the effect of them.

...Freedom arises from the multiplicity of sects, which prevades America and which is the best and only security for religious liberty in any society. For where there is such a variety of sects, there cannot be a majority of any one sect to oppress and persecute the rest.