Article VI, Clause 3:
The Senators and Representatives before mentioned, and the Members of the several State Legislatures, and all executive and judicial Officers, both of the United States and of the several States, shall be bound by Oath or Affirmation, to support this Constitution; but no religious Test shall ever be required as a Qualification to any Office or public Trust under the United States.
Although the Court has been divided in dealing with religiously based conduct and governmental compulsion of action or nonaction, it was unanimous in voiding a state constitutional provision which required a notary public, as a condition of perfecting his appointment, to declare his belief in the existence of God. The First Amendment, considered with the religious oath provision of Article VI, makes it impossible
for government, state or federal, to restore the historically and constitutionally discredited policy of probing religious beliefs by test oaths or limiting public offices to persons who have, or perhaps more properly, profess to have, a belief in some particular kind of religious concept.1