Peter was a fisherman, and fishermen have some good traits. However, at the end of the Gospel of John Jesus instructed Peter to become a shepherd. Quite a challenge, for shepherding is entirely different from fishing, and also Jesus has some extraordinarily peculiar sheep: Unkempt, dirty, awkward, pushy, and gone astray!
There are two ways to herd sheep. One way is with dogs. Dogs bark and snarl, chase the sheep, nip at their heels, and jump on their backs to get them to go in a direction.
On the other hand there is the good shepherd. He leads his sheep, calls them by name, feeds them, and tends to their needs.
The charge given to Peter in John 21 must become the charge to the church today. As Christians we must care for the flock, not like barking dogs, but like the good shepherd; leading people with Jesus words. Each of us has gifts from the Lord, and we are to use those gifts to protect and perfect the flock. In so doing we find ourselves with rejoicing hearts in our service to Jesus, and in turn He rejoices with us.