Jesus said: "I am the good shepherd. A good shepherd lays down his life for the sheep. A hired man, who is not a shepherd and whose sheep are not his own, sees a wolf coming and leaves the sheep and runs away, and the wolf catches and scatters them. This is because he works for pay and has no concern for the sheep. I am the good shepherd, and I know mine and mine know me, just as the Father knows me and I know the Father; and I will lay down my life for the sheep. I have other sheep that do not belong to this fold. These also I must lead, and they will hear my voice, and there will be one flock, one shepherd. This is why the Father loves me, because I lay down my life in order to take it up again. No one takes it from me, but I lay it down on my own. I have power to lay it down, and power to take it up again. This command I have received from my Father." -John 10:11-18
The wolf knows the Good Shepherd and knows that the Shepherd has the power to destroy him. But the wolf is hungry and wishes to devour the flock. As long as the Shepherd is near, the wolf will look elsewhere for his meal. Plenty of flocks have run away from the Shepherd and are unprotected; these are better for him to attack. Those who huddle closest to Our Lord remain the safest.
Let all nations know that Thou art God alone, and that Jesus Christ is Thy Son, and that we are Thy people and the sheep of Thy pasture.— St. Clement