In America, by Constitutional law, as per our First Amendment, there is no national imposed established religion, however, this did not originally mean, nor should it mean currently, that the individual States are precluded of having an established religion, State-supported as legislated by the State, as all of the original thirteen States had either an official religion or God belief as part of their State charter, at the time of the ratification of the Constitution. However, as time went on, most of the States voluntarily waived the established religion and religious requirements within their State, and with the passage of the 14th Amendment, and in particular its due process law, this has been interpreted by the Supreme Court in the years since, as meaning that no State of this union, shall be permitted to establish a religion, even though the establishment clause was to protect the States from the national government imposing a religion upon the people, not to preclude the States from having an established religion or a God belief within their State, which was the actuality at the time of the passage of the Constitution by these very same States.
In any event, notable Supreme Court rulings such as the Everson v. the Board of Education, has changed the context of religion in the public square, religion in governmental arenas, and religion in public schools, over the ensuring years, in such a manner, that the governmental court decisions and the implementation of them has in many ways, replaced religion, religious instruction, religious history, with secular and humanistic beliefs, or essentially irreligion, so that the end result, is that the United States has effectively made irreligion the established religion of this national government. That is to say, the courts and the national government have in many ways; in its fit and function prefer that students of public tax supported schools, as well as governmental facilities of all types, replace religion with irreligion, and to replace religious faith with secularism.
All of the above is supposedly done in a religiously neutral way, which means, in theory, that public schooling does not encourage religious belief or religious unbelief, but wants to keep religion, so to speak, out of the public marketplace. However, when religion is removed from the public sphere, when it cannot be discussed in a meaningful way or when the prism of history, or philosophy, or of everything that religion, ethics, and morality should have a say upon, has been negated, and thereby replaced by non-belief, and basic non-religion, such indoctrination of students and the public is functionally irreligious, untruthful, and dishonest.
To take God and religion out of the public sphere and out of public schools obviously creates a vacuum, which must of a certainty be replaced by something else. On the one hand, God and basic religious tenets teaches one the responsibility that we do not live to ourselves, that there is a greater power than us, that this power is our Creator, and from such we learn of appropriate ethics, morals, and of seeing all as our brothers and sisters. All of this is to the good of the individual, to the good of society, and to the good of civil government, but when God is forcibly removed from the public sphere, and replaced instead by irreligion and secularism, than it truly must be said, that anything goes, and that everything therefore is permitted, for laws are no longer created in conformance and recognition of natural law as universally provided to all through God, but are simply manmade laws, subject to the whims and tides of the time. This is the country that we now live in, once seen as a beacon for those seeking religious freedom, but now effectively replaced by irreligion and the destruction of a true moral compass.