The faithful labors of many Witnesses of Jesus Christ, extant to the world, abundantly proving, that the Church of the Jews under the Old Testament in the type, and the Church of the Christians under the New Testament in the Antitype, were both separate from the world; and that when they 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 at this day.

Roger Williams (1603?-1683) American clergyman and reformer

Mr. Cotton’s Letter, Examined and Answered (1644)
    (Source)

Writing of the blending of church and state, and resulting religious persecution, in Massachusetts. Likely origin of the "wall of separation between church and state" used by Jefferson.