There is no denying that in modern times that religion has come under attack. The Founding Fathers, however, understood the importance of protecting religion (not just "freedom of conscience") as a guiding principle of the United States. Many of the great moral advances in Western Civilization were created and promoted within the constructs of Christianity, including the moral ideas that eventually removed slavery from the United States. That is why, in the Bill of Rights, the very first clause of the very first amendment reads: "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof."
Before free speech, before the free press, before the right to assemble, before the right to keep and bear arms, the Bill of Rights enumerates the concept that Congress cannot prohibit the free exercise of religion.
Modern society rests on maintaining a government and a people capable of making and keeping moral associations. As John Adams put it:
“We have no government armed with power capable of contending with human passions unbridled by morality and religion. Avarice, ambition, revenge, or gallantry, would break the strongest cords of our Constitution as a whale goes through a net. Our Constitution was made only for a moral and religious people. It is wholly inadequate to the government of any other."When our government, and more importantly the people of the United States reject the religious foundations of morality, we condemn the United States to destruction as the moral principles of its founding are replaced by constructs which honor the dishonorable, uphold the weak, and replace evil for good.
The result will no longer be a constitutional republic, nor a democratic republic, but a despotism.