Archbishop Sample has misread the “establishment” clause of the First Amendment to the Constitution. As explained by the Supreme Court in Everson v. Board of Education, the establishment clause means that “neither a state or the Federal Government can set up a church,” nor can either of them pass a law which favors one religion over another or which mandates any kind of religious practice.
The basic idea was to make sure that the European concept of “divine right of kings,” which held, in effect, that the government decided the religion of all its subjects, did not take hold in the United States. The residue of this idea is still felt all over Europe, and especially in Germany, where Lutherans dominate in the north and Catholics dominate in Bavaria and other southern states. Neither the Oregon governor nor the Washington governor have violated the First Amendment when they called for common-sense practices to prevent the spread of COVID-19, such as limiting the number of people who could attend a church service.