I can't find in US Constitution where it says...

[Jim Lane]

37. Don't demand unreasonable specificity in a constitution.

I can't find in the U.S. Constitution where it says "Congress can provide by law that a little neighborhood barbecue place in the back streets of Birmingham must serve black people." Nevertheless, the Civil Rights Act of 1964 is constitutional.

I can't find in the U.S. Constitution where it says "Government may establish a single-payer health care system for some or all of the citizens." Nevertheless, Medicare is constitutional, and so would be a universal single-payer system.

Incidentally, my guess is that the Framers would have been flabbergasted at each of these exercises of federal power.

The takeaways are: (1) The Constitution uses broad, general terms. Otherwise, it could be 500 pages long and still not cover everything. Its broad, general terms must necessarily be interpreted, and sometimes there will be room for reasonable disagreement about the correct interpretation. (2) The interpretation can change over time as society changes.

To take one of your examples, about Christians and non-Christians: Is it constitutional for a government entity to provide maps for use in Catholic schools? Does the First Amendment prohibit that use of tax dollars (some of which come from us non-Christians)? It's not spelled out, either way. ("NotinConstitution" would include both the authorization and the prohibition.)

That prompts me to add a third takeaway: (3) Constitutional law can get complicated, and hard cases are not resolved by sloganeering.