The main point is that if man could look anywhere and not be confronted with the revelation of God then he could not sin in the biblical sense of the term. Sin is the breaking of the law of God. God confronts man everywhere. He cannot in the nature of the case confront man anywhere if he does not confront him everywhere. God is one; the law is one. If man could press one button on the radio of his experience and not hear the voice of God then he would always press that button and not the others. But man cannot even press the button of his own self-consciousness without hearing the requirement of God.
– Cornelius Van Til, Common Grace and the Gospel p.203