I know that the Supreme Court has said that in the past, but that doesn't make it the "correct" decision. It may be the law of the land for the time being, but that doesn't make it what the Constitution says.
The concept of precedent is fairly incompatible with a written constitution. Precedents are a system that are more suited for situations that involve common law so that you have something to go on, but when you have a statutory text to go on you should stick with the source when you make a decision.
Article IV.Section. 1.
Full Faith and Credit shall be given in each State to the public Acts, Records, and judicial Proceedings of every other State. And the Congress may by general Laws prescribe the Manner in which such Acts, Records and Proceedings shall be proved, and the Effect thereof.
Only Congress can define the effect by law (e.g., statute)...
It was landmark U.S. Supreme Court precedent Reynolds v. United States in 1878 that made “separation of church and state” a dubiously legitimate point of case law, but more importantly; it confirmed the Constitutionality in statutory regulation of marriage practices...