St. Mark the Ascetic ca. 5th cent.
There is an energy of Grace that is unknown to the neophyte (in the spiritual life); and there is another energy of evil that resembles truth. It is good for us not to reflect on these energies, since they may lead us into delusion; nor, again, should we dismiss them, because our ignorance of the truth; but we should lay everything before God in hope, for He knows what is of value in both of them. (The Evergetinos: A Complete Text. Vol. IV of the First Book, Hypothesis XLI, D.)