Nicene and Post-Nicene Fathers, Vol. II:
City of God: Chapter 12

Chapter 12.—Of the Miracles Wrought by the True God Through the Ministry of the Holy Angels.

Since by means of these arts wonders are done which quite surpass human power, what choice have we but to believe that these predictions and operations, which seem to be miraculous and divine, and which at the same time form no part of the worship of the one God, in adherence to whom, as the Platonists themselves abundantly testify, all blessedness consists, are the pastime of wicked spirits, who thus seek to seduce and hinder the truly godly?  On the other hand, we cannot but believe that all miracles, whether wrought by angels or by other means, so long as they are so done as to commend the worship and religion of the one God in whom alone is blessedness, are wrought by those who love us in a true and godly sort, or through their means, God Himself working in them.  For we cannot listen to those who maintain that the invisible God works no visible miracles; for even they believe that He made the world, which surely they will not deny to be visible.  Whatever marvel happens in this world, it is certainly less marvellous than this whole world itself,—I mean the sky and earth, and all that is in them,—and these God certainly made.  But, as the Creator Himself is hidden and incomprehensible to man, so also is the manner of creation.  Although, therefore, the standing miracle of this visible world is little thought of, because always before us, yet, when we arouse ourselves to contemplate it, it is a greater miracle than the rarest and most unheard-of marvels.  For man himself is a greater miracle than any p. 189 miracle done through his instrumentality.  Therefore God, who made the visible heaven and earth, does not disdain to work visible miracles in heaven or earth, that He may thereby awaken the soul which is immersed in  things visible to worship Himself, the Invisible.  But the place and time of these miracles are dependent on His unchangeable will, in which things future are ordered as if already they were accomplished.  For He moves things temporal without Himself moving in time, He does not in one way know things that are to be, and, in another, things that have been; neither does He listen to those who pray otherwise than as He sees those that will pray.  For, even when His angels hear us, it is He Himself who hears us in them, as in His true temple not made with hands, as in those men who are His saints; and His answers, though accomplished in time, have been arranged by His eternal appointment.