Wait....you mean Thomas Jefferson did NOT coin the phrase "separation of church and state" when referring to the 'free exercise of religion' clause of the 1st Amendment in his Danbury Baptist letter back over 100 years before FDR?
He wrote a letter. Big deal.
He said it wasn't his place as President to delcare days of public fasting and prayer (something Madison would later do, then regret).
As I understand it, Jefferson had no problem doing it as govenor of VA.
If that is true, what does that tell you ?