[ClearCase_guy]

I have known people who say that the words “Separation of Church and State” that appear in our Constitution really means that churchgoing Christians are not supposed to hold public office. George W. Bush, I was told several times, reduced this country to a theocracy, no different than Iran.

And, Yes, I did tell these people that the words “Separation of Church and State” do not appear in our Constitution. Bu they told me “that doesn’t matter”.

[5th MEB]

If I remember correctly those words only appear in the Federalist Papers; in the letters of the opposing camps on what should or would be admissible.
I could be wrong (memory isn't what it used to be).

[FatherofFive]

'Separation of Church and State' that appear in our Constitution

Those words aren't there. You are thinking of the Establishment clause.