11 What means “the world was made by Him”? The heaven, the earth, the sea, and all things which are therein, are called the world. Again, in another signification, those who love the world are called the world. “The world was made by Him, and the world knew Him not.” Did not the heavens know their Creator, or did the angels not know their Creator, or did the stars not know their Creator, whom the demons confess? All things from all sides gave testimony. But who did not know?
Those who, for their love of the world, are called the world. By loving we dwell with the heart; but because of their loving the world they deserved to be called after the name of that in which they dwelt. In the same manner as we say, This house is bad, or this house is good, we do not in calling the one bad or the other good accuse or praise the walls; but by a bad house we mean a house with bad inhabitants, and by a good house, a house with good inhabitants. In like manner we call those the world who by loving it, inhabit the world.
Who are they? Those who love the world; for they dwell with their hearts in the world. For those who do not love the world in the flesh, indeed, sojourn in the world, but in their hearts they dwell in heaven, as the apostle says, “Our conversation is in heaven.” Therefore “the world was made by Him, and the world knew Him not.”
Source: Tractates on the Gospel of John (New Advent)