Why did Jesus need to exorcise the world?

ANSWER!

If the church is the "Mystical Body of Christ," then the world is the "mystical body of Satan,"  As Christ's Mystical Body is a living community, intimately united to Christ the Head, the analogy of the world as the body of Satan is clear.  The world and the flesh and all those who serve these things, whether consciously or not, are united to the "prince of this world" and become vehicles for all the actions of the devil.  Explicit Satanism and devil-worship is the most evil expression of union with the devil, but there are many "worldly" people who serve the demonic agenda.  It was this world that Christ came to redeem because it was created good in the beginning and was corrupted by the devil and all his malice.

By Rev Thomas J. Euteneuer "Exorcism and The Church Militant" page 5