When the founders struggled to find common ground for the basis and direction for this country, one thing was never in question. The main reason for declaring the King of England's lack of authority was his rebellion against the principles of government as expressed by the Bible. Because the King would not allow the colonists to worship as they saw fit, they deemed rebellion against him an act of worship. The main purpose, then, was to allow Americans to worship Jesus freely.
For example, one restriction of the power of the federal government was to keep one denomination of Christians from stuffing their form of worship upon anyone else worshiping Jesus.
Another is the second amendment. The freedom to bear arms is mainly so we can defend ourselves against the governments we elect.