Jesus tells us – rather, He prays for us – that, while being “in the world” we not be “of the world.” (Cf. Jn. 17:11-19). Yet, we have feet of clay. We are more powerfully influenced by the things “of the world” than by spiritual things. It’s part of our fallen condition. It’s the same battle over and over again that each of the saints fought so fiercely; the same saintliness to which Vatican II reminds us that we, too, are all called:
The followers of Christ… are justified in the Lord Jesus, because in the baptism of faith they truly become sons of God and sharers in the divine nature, In this way they are really made holy. Then too, by God’s gift, they must hold on to and complete in their lives this holiness they have received… and to put on “as God’s chosen ones, holy and beloved a heart of mercy, kindness, humility, meekness, patience” (Col. 3:12), and to possess the fruit of the Spirit in holiness (Cf. Gal. 5:22; Rom. 6:22). [Lumen Gentium, The Dogmatic Constitution on the Church, par. 40]
A daily response to the Universal Call to Holiness does not come easy but we have a companion, an advocate, One who is the Way, the Truth and the Life, to not only assist us but guide us and care for us as a Good Shepherd.
The world does not know Him because the world is the dominion of satan. Once one of the brightest of all the angels, called Lucifer, the light bearer, he knew a lot but did not, and still does not know, the “secret and hidden wisdom of God, which God decreed before the ages for our glorification. None of the rulers of this age understood this; for if they had, they would not have crucified the Lord of glory” (1 Cor. 2:7-8).
The world does not know Him because satan does not know Him. Duped by God’s Wisdom, which he has never known, his spiteful jealousy leads us astray, but the Good Shepherd does not let the sheep who know Him stray too far, if we but listen to Him, knowing that “There is no salvation through anyone else, nor is there any other name under heaven given to the human race by which we are to be saved.”