See on v. 1. The shepherd constantly goes in and out among his sheep. The thief visits the flock only on rare occasions and for purely selfish motives, and ruins the flock.

Emphatic in the Greek in contrast with the thief.

 “Life” includes the physical, intellectual, and spiritual. Physical life is regarded as abundant in a body that is full of vigor and in perfect health. Jesus’ miracles of physical healing gave an abundant physical life to those whose life forces were ebbing. But physical restoration was by no means the complete fulfillment of Jesus’ mission. Man also has intellectual and spiritual life, which must also be made alive and abundant, for “man doth not live by bread only, but by every word that proceedeth out of the mouth of the Lord” (Deut. 8:3). Important as the physical and the intellectual aspects of a well-rounded life are, no life is fully complete unless the spiritual nature is nurtured.

 zōē, here used in its theological sense, equivalent to eternal life. When Adam and Eve were created they possessed zōē, but lost it when they sinned. True, their physical life was extended, but they were no longer conditionally immortal (see on Gen. 2:17). Jesus came to restore the zōē that Adam had forfeited (see on John 8:51).