The First Amendment to the United States Constitution guarantees freedom of religion. That is a fact. The First Amendment was ratified on December 15, 1791 as part of the Bill of Rights. The text of the First Amendment states:
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof...." [https://bit.ly/1zFG4Hh]. There is no debate about the text of the Amendment. These words were ratified by the several states and made part of the Constitution. The history of these words and the history of the ratification process, the product of a cooperative effort by many people in different state legislatures over a roughly contemporaneous period culminating in 1791, is irrefutable. There is no need for any leap beyond historical facts that everyone accepts.
On the contrary, the many different varieties of religious faith have sparked controversy, conflict and disagreement throughout history. The history of persecution of some religious groups by others was a principal motivation for the European migration to America, and subsequently, for the guarantee of freedom of religion in the United States Constitution. There is no framework of fact sufficient to establish the truth of any specific variety of religious belief. For that reason, a person who believes in any religion must go beyond what the facts can prove--they take a leap of faith.
Under our Constitution, each person has the right to decide for themselves whether or not to take a "leap of faith." The choice a person makes--whether to believe or not believe something beyond what the facts can support--has no impact on their status as a citizen. We are all guaranteed equal protection of the laws.
But the constitutional protection of religious belief is not a blank check. We do not, for instance, allow the practice of human sacrifice, even though that practice has been part of some religions in the past. The reasoning is obvious--the Constitution guarantees equal protection of the law to all, and that is inconsistent with allowing religious practice that harms non-believers.
For their part, non-believers sometimes act as if their reliance on facts--and by facts, I mean those statements whose truth can be verified independently using tests such as correspondence, coherence, repeatability and predictive power--makes them more worthy than believers. Facts definitely have more utility than faith in the realms of science, engineering, criminal justice and similar professions. However, the constitutional guarantee of equal protection of the laws applies equally to people acting on the basis of religious faith as well as to those acting on the basis of fact.
There is a bit of natural tension between religious faith and fact, but the two are not mutually exclusive because there are significant limits to what we know. Most of the matter and energy in the universe are "dark", and do not interact with light or other matter the same as ordinary matter and energy--we don't know what this stuff is! [2] Keeping what we can know to be true in perspective leaves room for reasonable people to choose faith, or not, and to tolerate those whose faith choice is different from their own. Indeed, even scientists can (and do) choose to take the leap of faith in realms they know are not governed by fact.
And the limits of factual knowledge leave plenty of room for faith, but not the overly specific faith that most religions espouse. There is a clear factual record that supports the current theory for the evolution of the life on earth from the Big Bang to homo sapiens. But in the words of astrophysicist Neil Degrasse Tyson, "What happened before the beginning? [We] have no idea..... religious people assert... that something must have started it all.... In the mind of such a person, that something is, of course, God." [3] The factual record leaves room for belief in God. It doesn't support the culturally-driven, anthropomorphic mythologies we generally associate with organized religion. And it definitely doesn't support persecuting one another over the differences between our various mythologies. In other words, the factual record demands toleration of differences in religious faith--because of all we don't know--it supports the First Amendment.
[1] www.google.com, dictionary; https://bit.ly/2Vb2q0v
[2] Tyson, Neil DeGrasse, Astrophysics for People in a Hurry, W.W. Norton & Company, New York, NY, 2017, pp. 59-60, 108-14.
[3] ibid., p. 32.