“Christian” is a noun, not an adjective. It’s possible to have a nation of Christians, but not a “Christian nation”.
“...the disciples were called Christians first in Antioch.” - Acts 11:26
It’s not nations, but disciples of Jesus who are called Christians. If we’ll use God’s words the way God does, we’ll avoid a lot of mistakes and confusion.
Exactly, I wholeheartedly agree. Probably 95% of Americans were Christian at its founding, but you cannot force people to the faith through legislation. The best way to preserve Christianity from a political perspective is for freedom of religion.