Jack, it doesn’t matter what separation of church and state means to me. The reality is that no one in America spoke of it to mean that American law is completely secular until atheism became popular in the 20th century. Schools had prayers, public places had biblical imagery, there were blue laws, and judges would sometimes quote the Bible (once even the gemara).
The first amendment doesn’t say that the country needs to be atheistic. It says that congress (not even the states…. that’s a separate issue; theoretically a state could be Christian, Muslim, etc..) shall not establish a national religion. The US cannot be a chrsitian country, but it can use christian principles, or other religious principles.
Again, the phrase “separation” was not ever once mentioned in the first amendment or tue constitution. Please do some cursory research and challenge the common perception that you heard in 5th grade civics class. It’s simply not true.