 Most Supreme Court justices have been Protestant Christians . These have included 33 Episcopalians , 18 Presbyterians , nine Unitarians , five Methodists , three Baptists , and lone representatives of various other denominations . William Rehnquist was the Court 's only Lutheran . Noah Swayne was a Quaker . Some 15 Protestant justices did not adhere to a particular denomination . Baptist denominations and other evangelical churches have been underrepresented on the Court , relative to the population of the United States . Conversely , mainline Protestant churches historically were overrepresented . 
