It is error alone which needs the support of government. Truth can stand by itself. Subject opinion to coercion: whom will you make your inquisitors? Fallible men; men governed by bad passions, by private as well as public reasons. And why subject it to coercion? To produce uniformity. But is uniformity of opinion desireable? No more than of face and stature. Introduce the bed of Procrustes then, and as there is danger that the large men may beat the small, make us all of a size, by lopping the former and stretching the latter.
Dang, it makes me nervous questioning Thomas Jefferson, but I think there may be a false premise... well, at least its not telling the whole story.
He claims that the reason for government coercion is to produce uniformity. That may be true, but it certainly isn't the only reason. Especially when regarding religious governmental coercion. Other reasons could include the belief that God would bless a country that was following His laws, or the honest wish to limit sin and evil in the world. Please note that these are reasons the religious might give. I realize that they would result in more uniformity, but the reason wouldn't be to produce uniformity.