The authority by which God governs all things is His autonomous authority. To say that God’s authority is autonomous is to say that God is a law unto Himself. He is not bound by some abstract system of law that exists outside of Himself or independent from Him (ex lex). Nor is God under some external law (sub lego); rather, He is a law unto Himself. This does not mean that He acts or behaves in an arbitrary manner. Rather, God’s activity is directed by God’s own character. And His character is completely righteous. All that He does flows out of His own internal righteousness. His external authority comes from His internal righteousness. In this sense God’s authority is intrinsic. It is found within Himself. It is not borrowed, delegated, or assigned from any other source.
R.C. Sproul