“. . . When you are alone you should know that there is present with you the angel whom God has appointed for each man. . . This angel, who is sleepless and cannot be deceived, is always present with you; he sees all things and is not hindered by darkness. You should know, too, that with him is God, who is in every place; for there is no place and nothing material in which God is not, since He is greater than all things and holds all men in His hand.
–St. Anthony the Great (Anthony of Egypt, lived 251-356).