Since intellectual creatures excel other creatures, as is clear from what was said above, we can readily understand that God governs all other creatures through the agency of intellectual creatures. Likewise, since some intellectual creatures excel others, God rules the lower through the higher. Accordingly men, who occupy the lowest place in the order of nature among intellectual substances, are governed by the higher spirits. These are called angels, that is, messengers, because they announce divine messages to men. Among angels, too, the lower are directed by the higher. For they are distributed among various hierarchies, or sacred principalities; and each hierarchy is divided into different orders.
St. Thomas Aquinas. (1265-1274). Compendium Theologiae: Government of Lower Intellectual Substances by Higher Intellectual Substances, trans. by Cyril Vollert. St. Louis & London: B. Herder Book Co., 1947
All scripture is given by inspiration of God and is profitable for doctrine, reproof, correction, and instruction in righteousness (2 Timothy 3:16).