We can be a Christian nation, or we can have freedom of religion, where no religion is preferred over another - pick one.
If evil happens because we "threw God out of the schools/government/families" whatever, then it must have been wonderful before that happened: no children ever died, nobody starved to death, there was no rape or torture, etc.
But that would have to have been a very long time ago, because neither recorded history nor even archaeologists have found evidence of it.