Question: "Why did Jesus tell Peter to "feed my sheep" in John 21?"
Answer: Jesus gave Peter a three-fold command to “feed my sheep” in John 21:15-17. Each time Jesus said, “Feed my sheep,” it was in response to Peter’s three-fold declaration of love for Jesus. The setting was one of the last of Jesus’ post-resurrection appearances to His disciples on the shores of the Sea of Galilee. Jesus prepared a breakfast of fish and bread for them, and then commissioned Peter with the task of feeding His sheep and tending His lambs.
The three commands, although often translated the same way, are subtly different. The first time Jesus says it, the Greek means literally “pasture (tend) the lambs” (v. 15). The Greek word for “pasture” is in the present tense, denoting a continual action of tending, feeding and caring for animals. Believers are referred to as sheep throughout Scripture. “For he is our God and we are the people of his pasture, the flock under his care” (Psalm 95:7). Jesus is both our Good Shepherd (John 10:11) and the Door of the sheepfold (John 10:9). By describing His people as lambs, He is emphasizing their nature as immature and vulnerable and in need of tending and care.
The second time, the literal meaning is “tend My sheep” (v. 16). In this exchange, Jesus was emphasizing tending the sheep in a supervisory capacity, not only feeding but ruling over them. This expresses the full scope of pastoral oversight, both in Peter’s future and in all those who would follow him in pastoral ministry. Peter follows Jesus’ example and repeats this same Greek word poimaino in his first pastoral letter to the elders of the churches of Asia Minor: “Be shepherds of God's flock that is under your care, serving as overseers” (1 Peter 5:2).
The third time, the literal translation is “pasture (tend) the sheep” (v. 17). Here Jesus combines the different Greek words to make clear the job of the shepherd of the flock of God. They are to tend, care for, and provide spiritual food for God’s people, from the youngest lambs to the full-grown sheep, in continual action to nourish and care for their souls, bringing them into the fullness of spiritual maturity. The totality of the task set before Peter, and all shepherds, is made clear by Jesus’ three-fold command and the words He chooses.
What is this food with which shepherds are to feed the flock of God? It can be no other than the Word of God. Peter declares that Christians are to desire the pure spiritual milk of the Word so that by it, we can mature in our salvation (1 Peter 2:2). As early as the book of Deuteronomy, we see the Lord describing His Word as food for His people who live not by bread alone, but by every Word that proceeds from His mouth (Deuteronomy 8:3). Jesus reiterates this thought in His temptation in the wilderness (Matthew 4:4). The importance of the Word of God as food for our souls cannot be over-emphasized.
Clearly, the job of the shepherds of God’s people is to provide them with the pure milk of the Word of God so they can move on to the meat and solid food of the spiritually mature (Hebrews 5:12-14). Pastoral ministry should be primarily one of pastors feeding their people the Word of God. Only then can pastors declare, as Peter did, their love for the Lord Jesus.