God, Government and Roger Williams' Big Idea - Smithsonian, Jan 2012
(It's a bit long but well worth the read)
When the colonies were started, the first people who came here were the puritans who escaped from religious persecution in Europe and wanted to start the colonies with their own version of religious doctrine, but enforced through colonial government. Roger Williams had a different and more radical idea. He saw that religion mixed with government tended to poison and corrupt religion (whereas now we almost see it more as the other way around). Williams saw how the other colonies were starting to shape up and started to speak up with his idea, he was persecuted for it. He founded the Colony of Rhode Island and Providence Plantation as almost a trial of sorts to see how his idea would play out. He wrote an exhaustive book detailing his vision of the separation of church and state, which later heavily influenced the founding fathers like Jefferson and Madison as they drew up the Constitution.
Some great quotes from Williams' book, The Bloody Tenet of Persecution, For Cause of Conscience, Discussed in a Conference Between Truth and Peace - 1644:
"When they [the Church] have opened a gap in the hedge or wall of separation between the garden of the church and the wilderness of the world, God hath ever broke down the wall itself, removed the Candlestick, etc., and made His Garden a wilderness as it is this day. And that therefore if He will ever please to restore His garden and Paradise again, it must of necessity be walled in peculiarly unto Himself from the world, and all that be saved out of the world are to be transplanted out of the wilderness of the World."
“It is the will and command of God that, since the coming of his Sonne the Lord Jesus, a permission of the most Paganish, Jewish, Turkish, or Antichristian consciences and worships, bee granted to all men in all Nations and Countries.”
“I infer that the sovereign, original, and foundation of civil power lies in the people.” The governments they establish, he wrote, “have no more power, nor for no longer time, than the civil power or people consenting and agreeing shall betrust them with.”
I find it terribly fascinating that the religious christians in this country are now the ones arguing for more public expression of religion, declaring that there is "no such thing as separation of church and state" (but what they really want is their religion in government and in public policy and in our schools), when it was a baptist theologian who first came up with the idea now held so precious by the secular portion of American society, as well as religious minorities. What the religious (christians) are really fighting for is their continued religious (christian) privilege over other religions and non-religions in this country.
Even though Williams' motive was entirely religious, his writings laid the groundwork for people during the enlightenment like John Locke and Thomas Jefferson, who later wrote in his letter to the Danbury Baptists in 1802 (referring the the establishment clause in the First Amendment to the Constitution):
"I contemplate with sovereign reverence that act of the whole American people which declared that their legislature should 'make no law respecting an establishment of religion, or prohibiting the free exercise thereof,' thus building a wall of separation between Church & State." (To read this entire letter, see the Intellects section above)
And the fight continues to this day, FFRF and other groups continue their efforts to pry the death grips of (christian) religion off of government affairs to keep it secular, to keep it separate from church influence. Williams was right, politics does soil religion. We are seeing it now with the new republicans, especially during this primary. But the other side of the coin is also true, religion soils government. In the words of the great Christopher Hitchens, "religion poisons everything". If we learn a little about our past, and the history of christianity especially, you see that religion had its chance in government affairs and ruined it for everyone. It set us back hundreds if not thousands of years of intellectual growth and prevented or delayed the recognition of universal human truths and liberties. Providence... it was named so because one could live there without fear of persecution of religious or non-religious beliefs, especially from their own government.
Roger Williams - Wikipedia
The Bloody Tenet of Persecution, For Cause of Conscience... - Wikipedia
Separation of Church and State in the U.S. - Wikipedia
Rhode Island - Wikipedia