Jesus is the "light of the world" who gives us the "light of life."  Christian life is a process of continual identification with Christ.  The effort to do this is not just behavioral modification but, perhaps more fundamentally, intellectual conversion.  To convert is to see things as Christ does, to come to have "the mind of Christ" as St. Paul puts it.  This is our defense against the "wiles of the devil" and a key to sharing in Christ's love.