George Mason played a key role in opposing Patrick Henry's 1785 Bill for the Support of the Teachers of the Christian Religion. In response to Henry's bill, Mason encouraged James Madison to author his famous Memorial and Remonstrance, then circulated copies of the Memorial throughout Virginia at his own expense.
http://press-pubs.uchicago.edu/founders/documents/amendI_religions43.html
“That Religion, or the Duty which we owe to our Creator, and the Manner of discharging it, can be directed only by Reason and Conviction, not by Force or Violence, and therefore all Men have an equal natural and unalienable Right to the free Exercise of Religion, according to the Dictates of Conscience, and that no particular religious Sect or Society ought to be favored or established by Law, in Preference to others” George Mason's proposed amendment to the Constitution.
That was a Virginia matter, what the heck does that have to do with the Bill of Rights?