lýkos occurs in the warning of Jesus against false prophets in Mt. 7:15. These teachers might produce notable achievements (the distinction is not merely that of word and deed) but they do not do the one thing that matters, i.e., the Father’s will. This is the criterion by which to differentiate appearance and reality. Paul has a similar saying in Acts 20:29, although it is impossible to say what false teachers he has in mind. As distinct from the church’s own teachers in v. 30, they come from outside… Jn. 10:12 again shows that the community is under mortal threat, but the focus is on the fact that Jesus, unlike the hireling, sees the threat, protects the flock with his life, and thus averts the danger. Faced with the threat, the flock may thus see to whom it truly belongs.
Kittel, G., Friedrich, G., & Bromiley, G. W. (1995, c1985). Theological dictionary of the New Testament. Translation of: Theologisches Worterbuch zum Neuen Testament. (540). Grand Rapids, Mich.: W.B. Eerdmans.