Pulse, Respiratory Rate, Temperature, Blood Pressure.
These have to be “within normal limits” (WNL) or life is threatened.
Institutions have vial signs too. For the Church, these four are listed in a super old and super important creed: One, Holy, Catholic, and Apostolic. All four are well-supported by Holy Scripture.
I like to outline these and compare them to Chick-fil-A for fun. Especially since some raving fans have an almost religious fervor for the franchise (I may or may not be one of them).
The Church is One. Though there are many denominations, true Christian churches acknowledge the validity of other Christian Churches as a local chapter of the One Church. Though there are many Chick-fil-A restaurants, There is only one company. If a store went rogue and started claiming they were the only “real” Chick-fil-A, they would rightly draw down the ire of the company with a cease and desist order.
The Church is Holy. This refers to the ethic of Christianity as expressed by the Ten Commandments, as taught by Christ and the New Testament. Churches are not authorized to revise the ethic and still be considered true Christian Churches. If a Chick-fil-A went rogue and started serving burgers instead of chicken they would lose their franchise.
The Church is Catholic. This means “universal” and refers to accessibility. The Church discriminates on the basis of the Gospel believed and lived and nothing else. If a church barred it’s doors from ethnic groups, or men or women, or children, or the poor–then it would no longer be catholic. If a rogue Chick-fil-A decided to stop serving middle aged men it would be a huge violation of the company’s catholicity, and that store would have to be corrected.
The Church is Apostolic. This means that it teaches the Gospel consistent with the Apostles’ Teaching–the Bible. If it denies the core teachings of Christianity, it’s no longer a church, but some sort of sub-Christian cult. The “Core Doctrine” of Chick-fil-A is “Eat More Chicken.” If a store changed this creed to “Eat More Beef” it would be heretical, and would probably lose its franchise.