The necessity of Scripture lies in the fact that man has broken the covenant of works. He therefore needs the grace of God. There is no speech or knowledge of grace in nature. God has accordingly condescended to reveal it in Scripture. The revelation of grace can be seen for what it is only if it be seen in its own light. The light of grace outshines in its brilliance the light of nature as the sun outshines the moon. The kind of God that speaks in Scripture can speak only on his own authority. So