They that were foolish took their lamps, and took no oil with them:
All Commentaries on Matthew 25:3 Go To Matthew 25
Augustine of Hippo
AD 430
What is the meaning of “took no oil with them”? What is “in their lamps”? In their hearts. For this reason the apostle wrote, “Indeed, this is our glory, the testimony of our conscience.” There is the oil, the precious oil. This oil is of the gift of God. We can put oil into our lamps, but we ourselves cannot create the olive. See, I have oil. But did I create the oil? It is of the gift of God. So you have oil. Carry it with you. What does it mean to “carry it with you”? To have it within, where it is pleasing to God. Note: those “foolish virgins, who brought no oil with them,” wish to please a human audience by that abstinence of theirs by which they are called virgins, and by their good works, when they seem to carry lamps. But wishing to please human spectators, doing praiseworthy works, they forgot to carry with them the necessary oil.