Our now common, but non-constitutional phrase [i.e., the words are not contained therein, but, many words are absent from the Constitution that we selectively choose to include] "separation of church and state," a.k.a.. "a high wall of separation." The "separation" phrase comes from the SCOTUS decision of Everson v. Board of Education, 1947 https://www.oyez.org/cases/1940-1955/330us1
Some claim it originats with Tommy Jefferson. However, at the time of drafting the Constitution, Tommy was separated from both church and state, as our minister to France. Yes, Tommy said the words, and believed them, but the concept of "separation" came from Roger Williams, a hundred years earlier in the 17th century.
What we only selectively remember, though I was reminded of the memory from high school, because we discussed it in my high school, and just seven years ago, read the full syllabus of the case [see the "Oyez" citation above. It contains, as part of the assenting decision, the following:
“…that although the United States government cannot promote religion, it also cannot be religion’s adversary.”
Be honest: did you know that was part of the decision? Sobering, considering the conflict that currently exists between the factions of "freedom of religion," because the 1st Amendment does not say that
government cannot cooperate with religion to improve our effort to become "a more perfect union," it just says government cannot "establish" a religion, that is, start one. Prayer does not establish a religion. Talking about religion does not establish one. Come on, words mean things. Need a dictionary?