For all the heads of true doctrine are not in the same position. Some are so necessary to be known, that all must hold them to be fixed and undoubted as the proper essentials of religion: for instance, that God is one, that Christ is God, and the Son of God, that our salvation depends on the mercy of God, and the like. Others, again, which are the subject of controversy among the churches, do not destroy the unity of the faith;
