We live in a nation in which the Constitution does not mention God. Many on the left have used this fact to argue that the United States is a secular nation. They then expand on this to justify banning all religious expression from any government forum, including public schools.
History teaches us otherwise. The Constitution excluded mention of God, not because the Founders were irreligious, but quite to the contrary, they were all members of various and sundry religious establishments, and wished to keep it that way. They reasonably feared that if the government were allowed to define God, then Religious Freedom would be lost.
This is why the Establishment Clause of the First Amendment is balanced against the Free Exercise clause. Both are necessary, not for the exclusion of religion, but for its protection. The Founders rightly insisted upon both principles. Each of them protects the other.
That history has been turned on its head. Liberal Progressives now interpret the Establishment clause so expansively that, in their view, it crowds out Free Exercise so completely as to render it of no effect. The end result is what we see now, a God Derangement Syndrome in which even the remotest hint of tribute to God is frantically opposed by the Left. Every smallest symbol of a cross is being scrubbed from official seals, lest anyone be offended. Those offended by the removals are considered to be of no account.
By contrast, the Declaration of Independence attributes our "inalienable rights" to our "Creator," not to the government. Prior to that, an earlier founding document, the Mayflower Compact, specifically credits God-the Christian God-whose worship is the very purpose of the fledgling American government.
Ironically, it seems that the only religion that the Left deems worthy of protection is the one major world religion that stands diametrically opposed to religious freedom, and indeed, to all the founding principles of equality and liberty which Americans have died to preserve. It is not that liberals worship the God of that religion, nor of any other (with the possible exception of the goddess, Mother Earth), but rather, that they regard Islam as a vehicle for tearing down the traditions of Western Civilization, and thereby destroying our nation.
Finally, in yet another self-contradiction, liberals seem increasingly to worship physical science. It is no coincidence, then, that science, which was formerly considered independent and single-mindedly objective, is increasingly subordinated to the service of leftist propaganda with bias and even outright falsehoods. We see this today in the ostracism of any scientist who even so much as questions the quasi-religious doctrine of global warming/cooling/change, but also a few years ago during the AIDS epidemic. Thousands lost their lives because it was feared that homosexuals would be offended by the truth, if the facts presented by AIDS dissidents were released to the public. See here and here.
This hijacking of science by the left is subtly employed to promote the philosophy of physicalism, in which everything in the physical universe is permitted to be explained only in physical terms, and by nothing else. This circular reasoning fails utterly to explain the most fundamental and pervasive of all objective observations, that of our inward experience of consciousness. It goes further. Physicalism is utterly incompatible with the perception that we have free will, by which we can overcome at least some of the constraints that cause-and-effect place upon our moral choices. The logical conclusion from this idea is that we are unaccountable for our deeds, which is ironic, since leftists blame conservatives for all the imperfections in our society, even theirs.
When we get right down to it, the dark heart of Liberal Progressivism denies our very humanity.