The fundamental idea of puritanism in all its manifestations was the supreme authority of Scripture brought to bear upon the conscience as opposed to an unenlightened reliance on the priesthood and the outward ordinances of the Church.
The puritan, whether narrow or broad, mistaken or enlightened, seemed, to himself at least, to be aiming, not at singularity, but at obedience to that higher spiritual order prevailing in the universe, which he recognised as being the expression of the mind of God, and therefore of more commanding authority than the mere arrangements and requirements of man.
John Brown. The English Puritans.