Starting with: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; " most of the cases that have been brought to the court system about this clause have nothing to do with Congress. A city government putting up Christmas lights in December has nothing to do with Congress...so all of those cases which have already been adjudicated to be in violation of Church and State are wrong. A sports team voluntarily praying before a game - no violation there either. A city with the word Saint in its name - no violation because Congress did not do any of these.
This is the full text of the First Amendment to the U.S. Constitution; the first of the Bill of Rights. Note the first clause, of the First Amendment:
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
I wanted to get the specific language of what we generally refer to as the "Freedom of Religion" on the table, because...
Amendment 14 ratified 1868
Limits state laws allowed
Right to vote modified for states participated in rebellion
Limits who may hold office in states participated in rebellion
The government nor any state shall pay debts arising from rebellion
Rebellion loss claims are illegal and void