The Intent of the Founding Fathers
Besides reading, understanding and knowing the Constitution (I do not know all of what the Constitution says, but I have read it and cherish the Bill of Rights especially), we should also seek to understand the intent of the the Founding Fathers. Anti-God organizations and individuals love to cite "separation of church and state," which was not ever mentioned in the Constitution, not even one time. In fact, this saying comes from a private letter from Thomas Jeferson to a Baptist church, guaranteeing the church that the government cannot restrict their worship in public places because there is a wall of spearation between church and state.
Read the minutes to the Continental Congress of 1787 and learn what the Founding Fathers discussed before approving each amendment to the Constitution. Do not let ignorant anti-God bullies convince you that our country was founded by Atheists; Benjamin Franklin was one of the only anti-religion, anti-God founders, while the great majority of them were God-loving, deeply religious Christians. The first Congress translated the Bible from the original languages into modern-day English and recommended the translation be used by all Americans, including schools! So although they were against a state-dictated denomination, they were for religion being taught in the schools and being kept in the public sphere.
For a better explanation, read David Barton's America's Godly Heritage, and visit his Wall Builders website.
Journals of Congress 1789-1873 on the LOC.gov website.