Quotes from Justice Potter Stewart

The right to defy an unconstitutional statute is basic in our scheme. Even when an ordinance requires a permit to make a speech, to deliver a sermon, to picket, to parade, or to assemble, it need not be honored when it's invalid on its face.

The state may not establish a 'religion of secularism' in the sense of affirmatively opposing or showing hostility to religion, thus 'preferring those who believe in no religion over those who do believe.