The U.S. Constitution says nothing about separation of church and state. It is just not there. All it says about religion is, “Congress shall make no law ...” As long as Congress makes no law concerning religion, the First Amendment is satisfied.
Also, the national motto is, “In God We Trust.” We pledge our allegiance to “One Nation Under God.” The U.S. Senate starts each session with a prayer, the national motto is above the speaker’s rostrum in the U.S. House and the Ten Commandments are on the Supreme Court building.
The founders obviously did not intend to remove religion from public life. Anyway, the U.S. Constitution only applies to government, not to private citizens, wherever they are.