In the Old Testament, numerous lambs were raised and matured for the solitary purpose of being slaughtered upon the altar of God. In caring for these lambs, some of them likely were known intimately by the family as a they were fed, tended, and raised (sometimes as a beloved pet), thus magnifying the depth of pain brought about in the atonement process–the killing of the beloved animal being a result of the sin that needed to be washed away. In the New Testament, the sacrifice carried an even more profound reality when understood in light of the Son of God giving Himself to make atonement for our sin.
There could be no more profound relationship than the Son of God–the Creator of the Universe and the Life-Giver of mankind–giving His beloved Son for our redemption. So, in truly understanding the reality of sacrifice–we see not only death and atonement for sin but the incredible intimacy of that great act of taking one life in order to spare another. Jesus modeled that so well–and His followers have a responsibility to imitate His life-giving sacrifice through the way that they glorify God and serve one another. The Spirit of Christ in us compels us to lay down our lives for His sheep… just as our beloved Shepherd did for us.
“Israel’s sheep were reared, fed, tended, retrieved, healed, and restored–for sacrifice on the altar of God. This end of pastoral work must never be forgotten–that its ultimate aim is to lead God’s people to offer themselves up to Him in total devotion of worship and service.”
In other words, the pastor’s greatest work is to prepare the flock of God to sacrifice their lives unto Him, in all of their work, for His glory. He must encourage, exhort, and model a lifestyle of being slaughtered for the sake of Christ–the faithful disciple is called to deny Himself and take up His cross.
 William Still, The Work of the Pastor (Ross-Shire: Christian Focus Publishing, 2011), 17.