You probably should study a bit more. The Founders understood that this was a Christian nation. The Supreme Court declared it so by unanimous decisionin February 1892:<<If we pass to a view of American life, as expressed by its laws, its customs, and its society, we find everywhere a clear recognition of the same truth... that this is a Christian nation.>>
Go read Justice Brewer's book "The United States, a Christian Nation", in which he explains what the Supreme Court intended by this statement.
Justice J. Story declared, << Christianity is part of the Common Law, from which it seeks the sanction of its rights... the Common Law recognizes Christianity as its foundation.>>
Justice J. McLean stated that <<the perpetuity of the institutions rests upon Bible morality and the general dissemniation of Christian principles. Our mission of freedom is not carried out by brute force, by church law, or any other law except the moral law and those Christian principles found in the Scriptures>>.
Chief Justice E. Warren stated that <<Whether we look to the first Charter of Virginia, or the Charter of New England, [etc. etc.] the same objective is present: a Christian land governed by Christian principles. The Entire Bill of Rights came into being because of the knowledge our forefathers had of the Bible and their belief in it...we are living today in the spirit of the Christian religion.>>