“The eyes of the Lord are in every place, beholding the evil and the good (Prov. 15:3). Oh, if only rational creatures would always keep this in mind! Then not only would they not dare to commit excesses openly and to give themselves over to dissoluteness of the flesh, but also inwardly, in their thoughts, and in the movements of their heart, they would not allow anything unpleasing to God. They would stand then like soldiers at the front before the king, with all attention and strictness toward themselves, that they not be found ignorant of their orders, and not be subject to the king’s wrath and punishment. The orders given to rational creatures are the commandments of God, which determine the proper form of their thoughts, and how their feelings and dispositions ought to be; they would then be quite well-ordered.”
- Saint Theophan the Recluse
Reference: http://days.pravoslavie.ru/en/Days/20120313.htm