These are some notes on John 21, following up on a sermon from a few years ago:

1. Note that Jesus not only accepts Peter, he accepts an imperfectly repentant Peter. When Jesus includes Peter in his meal on the beach, he is showing Peter that he is forgiven, restored, and reconciled. The threefold question, "Do you love me?" in chapter 21 cancels out the threefold declaration "I am not his disciple" in chapter 18. Three affirmations of love answer the three denials. But even then, Peter seems to have a struggle. He has not totally gotten past his rivalry with the Beloved Disciple, John, as is seen in 21:20ff. Jesus reminded Peter that he needed to have tunnel vision, focusing only on what God has in store for himself, minding his own duty, and not concerning himself with whatever prosperity or suffering God might have planned for others.
As I said on Sunday, Peter had really messed up when he denied Jesus. He knew he was no longer worthy to be a disciple, much less an apostle. But the fact is, most of us are not that different from Peter. I'm sure I have done (or thought) things that, if you knew about them, you would not want to come to a church where I am the pastor. And I'm sure you've done (or thought) things that, if I knew them, I might be a little concerned about having you in my congregation. But Peter's story is recorded for all of us. His restoration to fellowship and leadership is pure grace. It demonstrates the love that God extends to each one of us. The church is, and will always be, a place where sinners should be welcome. That's not to say there are no standards or requirements or demands -- there most certainly are! -- but those follow rather than lead. God insists on our transformation, but that transformation is a post-condition, not a pre-condition, to our reconciliation. The transformation flows out of our initial acceptance.
This free acceptance is right at the heart of the gospel. But God not only accepts our persons in Christ, he also accepts our works in Christ. Even your imperfect repentance is accepted by him. Even your ongoing struggle with sin (provided it really is a struggle!) is pleasing to him. Even your flawed, sin-stained efforts are his delight. The Christian life is not a matter of trying hard to make ourselves right with God, but rather, having been made right with God, following Paul in 1 Cor. 15, "we work harder than all the rest." God says to us not only "Your sins are forgiven!" but "Well done good and faithful servant!" We may say about ourselves, "We are unprofitable servants," but God considers our work in Christ to be very profitable.
God uses all kinds of people to do his work in the world. God uses imperfect people. He used Mary, the one who had been demon possessed, to make the original annoucement of the empty tomb. He used Thomas the Doubter to make the ultimate confession of faith. And he used Peter, the Denier, to be one of the chief apostles of the early church. Surely, then, God can use each of us, whatever our shortcomings. The message of John 21 is clear: "Stop moping around and get to work! Stop beating yourself up and start serving!"
Peter had to learn to let go of his past failings. He had to break free of his past shame so he could move ahead into the glorious future God had in store for him. All too often, Christians become prisoners of their past sins, and they never really become effective servants in the kingdom because all they see is what they do wrong. I call this "worm theology" -- all you see about yourself is that you a worm compared to the holiness of God. While it is important to have a healthy grasp of our shortcomings, it is equally important that we remember that we are now a new creation in Christ. We have a new identity in him. The old things are gone; the new have come. We're not chained to the past; we can go forward in hope and confidence. We're not worms; we're saints.  It's interesting to note that the Bible never uses ther label "sinner" to describe God's faithful people. Of course, we do sin -- but sin no longer defines us once we are united to Christ. We are accepted by God, and that acceptance sets us free to do what we've been called to do.
Because God accepts our persons in Christ, he accepts our works in Christ. Because we are so accepted, we can go out into the world to do his work full of joy and confidence....which is what Peter did. The gospel is comprehensive -- God not only saves you, he saves your work. He incorporates you into Christ and weaves your work into the maturation of his kingdom. The encounter with Jesus in John 21 changed everything for Peter, and it can for us as well. Having been fed and forgiven, Peter went out to offer food and forgiveness to others. We've been given the same and we're to do the same. That brings me to my next point.
2. We are to live as God's "sent ones." We are "on a mission from God." Like the other gospels, the end of John enphasizes the new phase of God's work in the world, and the church's inclusion in that work, as she is called to disciple the nations.
This mission is empowered by Christ's Spirit. When Jesus dies on the cross in Jn. 19:30, it says he "gave up His Spirit." What is "His Spirit"? We are not overreading the text if we see this as more than a reference to his human death departing from his body at death. This is Jesus giving the Holy Spirit to his people, through his death. It's a proto-Pentecost (similar to Jn. 20:22, another anticipation of Pentecost). The gift of the Spirit (life) flows out of Christ's death. The Spirit drives the mission of Christ forward in the world through the church. Christ was sent by the Father. Christ now sends the Spirit. And if the church is united to Christ and given the Spirit, she is sent as well. Because Christ is with us in the Spirit, the church's mission is assured of success. The Spirit enables us to get the job done.
From another perspective this mission is empowered by the means of grace (Word, baptism, sacrament). Once again, Peter is emblematic. Jesus gives Peter a meal (Jn. 21:13) to strengthen him before giving him his apostolic job description (Jn. 21:15ff). Jesus gathers us at his table precisely so he can send us out to do his work. In that sense, you can say that the meal is not only a means of communion, but of commissioning. Because we have communed with Christ at his table, we can go out into the world like Peter, ready to share in Jesus' mission and martyrdom.
3. There is another important detail regarding our mission in Jn. 21:11.
The church's mission is pictured by fishing. When we think of fishing, we usually have in mind an individual using a rod and reel. But fishing in the Bible is a bit different. They fished with nets, which required a team effort. Fishing with nets requires a group to work together.
That is to say: Fruitful mission is inseparable from unity. Mission is a community project.
In 21:11, when Peter pulls the net up, it says the net did not tear. Literally, it says there was no "schism" in the net. The net did not split. Had the net torn, all the fish would have been lost. That is to say: Only a unified church (an untorn net!) can can get the catch. Schism destroys mission. The fishermen have to work together; the net has to stay in one piece.
If the church in the West is stagnating and even declining in its ability to reach the lost, perhaps it's because our nets have been torn into denominational shreds. We don't have an untorn net. Instead, we have Presbyterian nets, Baptist nets, Anglican nets, etc. And even when we break down into our denominational subcultures, we don't get along very well. We've ripped the nets of mission. If we're going to rehabilitate the church in our part of the world, we have to learn to manifest our oneness in Christ.
You can think of it this way: Community and mission are to the church what size and color are to a shape. There is no such thing as a shape without size and color. In the same way, there is no true church without community and mission. These are the fundamental dimensions, or aspects, of life as the covenant people. Without community, we cast our nets in vain. But a community that doesn't fish together is hardly a community at all.
4. Speaking of community and mission....I think it is worth reflecting a little more on the mixed metaphors John 21 uses to describe the church's work. John 21 uses the metaphors of fishing (21:1-14) and shepherding (21:15-19). Fishing is mission. It's evangelism. We're fishers of men, fishers of nations. Shepherding is discipleship. It's nurture. It's word, sacrament, and discipline. These tasks may apply especially and fully to church leadership. But in some way, they are applicable to all Christians. We're all to be engaged in mission, casting the net of the gospel to draw others in. And we're all to be engaged in shepherding and discipling one another, as we encourage and admonish one another from the word.
Some people may be more gifted as fishermen, others more gifted as shepherds. But every church is called to excel in both. There are fish that need catching and sheep that need tending -- that's our vocation.
5. Our success in mission requires both the work of God and the work of the church.
In John 6:44 , Jesus says "No one is able to come to me unless the Father who sent me DRAWS [or DRAGS] him."
In John 21:11, the same Greek word "dragged" is used to describe Peter's action with the fish net. He DRAGGED the fish up to Jesus.
So who drags the fish in? The Father? Or the church? 
This is a good example of God's sovereignty and human responsibility meshing together. God has planned and controls everything that comes to pass. Sinners only come to Christ as they are drawn by the sovereign grace of God.
At the same time, that does not mean that we're to just sit back and let God do all the work. We're not supposed to say, "Well, God does the drawing, so there's nothing for us to do." Rather, we should see that God draws people to himself through us.
Only God can give us a catch. But that does negate our responsibility to cast the net and draw the fish in. God makes the mission successful, but he uses means, including our evangelistic efforts.
6. A popular preaching strategy in John 21 is to point out the different words used for love in the exchange between Jesus and Peter in 21:15ff. In the Greek, there are several terms which can be translated into English as "love." Two of them are used in this passage. The first is "phileo," which especially points to "brotherly love." The second term is"agape," which is a more general term, and probably puts the accents the sacrificial nature of love.
The first two times Jesus asks the question, he uses "agape." The third time, he uses "phileo." Every time Peter answers, he uses "phileo."
Is this merely a stylistic variation? Or is there some profound theological point being made here?
It's hard to say. Remember, Jesus almost certainly spoke Aramaic, not Greek, and the Aramaic vocabulary for "love" was not nearly so refined. So if there is a more subtle point, John is bringing it out of the non-verbal nuances of the conversation as it took place.
But the problem is that, while there may be different shades of meaning with "phileo" and "agape," there is also considerable overlap. Most of the time, when the differences in the terms are brought out, "agape" is regarded as the higher form of love. But then why is "phileo" used in the third and climatic question and answer? Besides, it is not at all certain that "agape" would have really been considered a deeper or more loyal form of love. Exactly how is "sacrificial love" different from "brotherly love"?
Along with most of the commentators, I think there is very little theological and practical significance to the variation in vocabulary here. Or, if there some deeper point, I have yet to discover it. More likely, this is stylistic. That would not be unusual for John as a writer, since he seems to do the same thing elsewhere.
7. From the "I'm not insane" department--
On the number 153, Jim Jordan has a pretty good essay:
But it's not just Jim.
Rob Rayburn's sermon covers the same ground:
As does Doug Wilson:
In fact, I was pleasantly surprised to see how many of the commentaries on John were willing to deal with the symbolic depth of the number 153. John 21 as a whole is a very symbolically thick text, and many of those symbolic features are overlooked. But I was glad to notice that recent commentators have essentially reached a consensus on the meaning of this number.
While the use of triangulation (17+16+15+14....=153) and gematria (the numerical value of words) seems weird to us, there is almost no doubt these things are present in the passage. The number "153" pops out at you from the text, and cries for an interpretation. There are just too many easy-to-find connections to be merely coincidental.