Constitutional FAQ Answer #71
Q71. "I cannot find anywhere in the Constitution that refers to separation of church and state."
A. Though many people assume the 1st Amendment sets out some separation, the phrase does not appear in the Constitution. The phrase "wall of separation" appears to have been coined by Jefferson, in speaking of the religious liberties granted by the Constitution and the Bill of Rights. Madison, however, said that there is a line between church and state, not a wall — the distinction may or may not be significant.
In practice the separation is more theoretical than actual. In a truly separate society, we would not invoke the name of God on our currency, nor would we speak so highly of our Judeo-Christian values. But we do — the fact of the matter is, completely separating religion and government is probably impossible, so long as religion is an important part of the lives of the citizenry. The best we can hope for, and what I think the Constitution tries to protect, is to ensure that there is no discrimination on the basis of religious belief — that there be no religion litmus test.