This case is perhaps the most important religious liberty opinion issued by the Supreme Court, if for no other reason than the fact it has been followed or relied upon, directly or indirectly, by most important cases over the subsequent 150 years. The Court held that questions of religious doctrine, belief, discipline or membership were solely matters of internal ecclesiastical governance and beyond the cognizance or power of courts or government to disturb:
“The rule of action which should govern the civil courts … is, that, whenever the questions of discipline, or of faith, or ecclesiastical rule, custom, or law have been decided by the highest of these church judicatories to which the matter has been carried, the legal tribunals must accept such decisions as final, and as binding on them, in their application to the case before them.”
Watson was not a constitutional case, but was based on American common law. That was because, at the time, the First Amendment was still deemed to apply only to the federal government; only in 1940 did the Supreme Court decide that the Fourteenth Amendment “incorporated” the Free Exercise and Establishment Clauses of the First Amendment to apply to the states. Nevertheless, the Court in Watson deemed the principles it announced to be so fundamental to American concepts of religious liberty as to be binding upon all branches of government as a matter of common law. Decades later, the Supreme Court recognized the compelling constitutional support for Watson and held that it was entitled to such treatment.