Religion has a definitive clause somewhere in federal law.

For the US, a person's rights regarding religion are not enshrined in law but in the Constitution. This is a very important distinction.

Laws are made by Congress (either state or federal), executed by the President (or governor), and any disputes are handled in the courts. Laws may be changed by the majority or Congress and the President may execute laws or not execute laws within the scope of his or her authority. On the other hand, a constitutional right may not be encroached by Congress, the President, or a court.

If a person does something illegal and claims that he must not pay a fine / go to jail / etc. because of his or her religion, then courts must weigh this claim very heavily. They have not always taken the individual's side, but they do take the individual's side often enough for people to believe that the Constitution is still a meaningful document in this country.

Religion has a definitive clause somewhere in federal law.

For the US, a person's rights regarding religion are not enshrined in law but in the Constitution. This is a very important distinction.

Laws are made by Congress (either state or federal), executed by the President (or governor), and any disputes are handled in the courts. Laws may be changed by the majority or Congress and the President may execute laws or not execute laws within the scope of his or her authority. On the other hand, a constitutional right may not be encroached by Congress, the President, or a court.

If a person (or employer, shopkeeper, public official, etc.) does something illegal and claims that he or she must not pay a fine / go to jail / etc. because of his or her religion, then courts must weigh this claim very heavily. They have not always honored such claims, but they do take the claimant's side often enough for people to believe that the personal right to practice any religion may very well be a valid defense.