If everyone claimed a religious exemption, wouldn’t religion become a law unto itself?
The US Supreme Court has described two situations in which Courts cannot ignore a laws burden on religious practice, where the law appears to be facially neutral. The first situation is where a law has built into it exemptions requiring individual assessments, (like the animal permit exemption). The second is a ‘hybrid rights’ claim, where the law burdens not only freedom of religion, but also other important constitutional protections, such as freedom of speech.