These verses reveal what it means to love Christ, to truly understand the duties the under-shepherd has over the sheep; to love them enough to 'feed' them, regardless of the trials and tribulations that are sure to come. Peter was 'put to the test' as our Lord teaches him, and us, much from these verses. Matthew Henry's commentary on these verses is excellent...
"If we would try whether we are Christ's disciples indeed, this must be the enquiry, Do we love him? But there was a special reason why Christ put in now to Peter. 1. His fall had given occasion to doubt of his love: “Peter, I have cause to suspect thy love; for if thou hadst loved me thou wouldst not have been ashamed and afraid to own me in my sufferings. How canst thou say thou lovest me, when thy heart was not with me?” Note, We must not reckon it an affront to have our sincerity questioned, when we ourselves have done that which makes it questionable; after a shaking fall, we must take heed of settling too soon, lest we settle upon a wrong bottom. The question is affecting; he does not ask, “Dost thou fear me? Dost thou honour me? Dost thou admire me?” but, “Dost thou love me? Give but proof of this, and the affront shall be passed by, and no more said of it.” Peter had professed himself a penitent, witness his tears, and his return to the society of the disciples; he was now upon his probation as a penitent; but the question is not, “Simon, how much hast thou wept? how often hast thou fasted, and afflicted thy soul?” but, Dost thou love me? It is this that will make the other expressions of repentance acceptable. The great thing Christ eyes in penitents is their eyeing him in their repentance. Much is forgiven her, not because she wept much, but because she loved much. 2. His function would give occasion for the exercise of his love. Before Christ would commit his sheep to his care, he asked him, Lovest thou me? Christ has such a tender regard to his flock that he will not trust it with any but those that love him, and therefore will love all that are his for his sake. Those that do not truly love Christ will never truly love the souls of men, or will naturally care for their state as they should; nor will that minister love his work that does not love his Master. Nothing but the love of Christ will constrain ministers to go cheerfully through the difficulties and discouragements they meet with in their work, 2Co_5:13, 2Co_5:14. But this love will make their work easy, and them in good earnest in it.
Secondly, Lovest thou me more than these? pleion toutōn. 1. “Lovest thou me more than thou lovest these, more than thou lovest these persons?” Dost thou love me more than thou dost James or John, thy intimate friends, or Andrew, thy own brother and companion: Those do not love Christ aright that do not love him better than the best friend they have in the world, and make it to appear whenever they stand in comparison or in competition. Or, “more than thou lovest these things, these boats and nets - more than all the pleasure of fishing, which some make a recreation of - more than the gain of fishing, which others make a calling of.” Those only love Christ indeed that love him better than all the delights of sense and all the profits of this world. “Lovest thou me more than thou lovest these occupations thou art now employed in? If so, leave them, to employ thyself wholly in feeding my flock.” So Dr. Whitby.
2. “Lovest thou me more than these love me, more than any of the rest of the disciples love me?” And then the question is intended to upbraid him with his vain-glorious boast, Though all men should deny thee, yet will not I. “Art thou still of the same mind?” Or, to intimate to him that he had now more reason to love him than any of them had, for more had been forgiven to him than to any of them, as much as his sin in denying Christ was greater than theirs in forsaking him. Tell me therefore which of them will love him most? Luk_7:42. Note, We should all study to excel in our love to Christ. It is no breach of the peace to strive which shall love Christ best; nor any breach of good manners to go before others in this love.
Thirdly, The second and third time that Christ put this question, 1. He left out the comparison more than these, because Peter, in his answer, modestly left it out, not willing to compare himself with his brethren, much less to prefer himself before them. Though we cannot say, We love Christ more than others do, yet we shall be accepted if we can say, We love him indeed. 2. In the last he altered the word, as it is in the original. In the first two enquiries, the original word is Agapas me - Dost thou retain a kindness for me? In answer to which Peter uses another word, more emphatic, Philō se - I love thee dearly. In putting the question the last time, Christ uses that word: And dost thou indeed love me dearly?
(2.) Three times Peter returns the same answer to Christ: Yea, Lord, thou knowest that I love thee. Observe,
[1.] Peter does not pretend to love Christ more than the rest of the disciples did. He is now ashamed of that rash word of his, Though all men deny thee, yet will not I; and he had reason to be ashamed of it. Note, Though we must aim to be better than others, yet we must, in lowliness of mind, esteem others better than ourselves; for we know more evil of ourselves than we do of any of our brethren.
[2.] Yet he professes again and again that he loves Christ: “Yea, Lord, surely I love thee; I were unworthy to live if I did not.” He had a high esteem and value for him, a grateful sense of his kindness, and was entirely devoted to his honour and interest; his desire was towards him, as one he was undone without; and his delight in him, as one he should be unspeakably happy in. This amounts to a profession of repentance for his sin, for it grieves us to have affronted one we love; and to a promise of adherence to him for the future Lord, I love thee, and will never leave thee. Christ prayed that his faith might not fail (Luk_22:32), and, because his faith did not fail, his love did not; for faith will work by love. Peter had forfeited his claim of relation to Christ. He was now to be re-admitted, upon his repentance. Christ puts his trial upon this issue: Dost thou love me? And Peter joins issue upon it: Lord, I love thee. Note, Those who can truly say, through grace, that they love Jesus Christ, may take the comfort of their interest in him, notwithstanding their daily infirmities.
[3.] He appeals to Christ himself for the proof of it: Thou knowest that I love thee; and the third time yet more emphatically: Thou knowest all things, thou knowest that I love thee. He does not vouch his fellow-disciples to witness for him - they might be deceived in him; nor does he think his own word might be taken - the credit of that was destroyed already; but he calls Christ himself to witness, First, Peter was sure that Christ knew all things, and particularly that he knew the heart, and was a discerner of the thoughts and intents of it, Joh_16:30.
Secondly, Peter was satisfied of this, that Christ, who knew all things, knew the sincerity of his love to him, and would be ready to attest it in his favour. It is a terror to a hypocrite to think that Christ knows all things; for the divine omniscience will be a witness against him. But it is a comfort to a sincere Christian that he has that to appeal to: My witness is in heaven, my record is on high. Christ knows us better than we know ourselves. Though we know not our own uprightness, he knows it.
[4.] He was grieved when Christ asked him the third time, Lovest thou me? Joh_21:17. First, Because it put him in mind of his threefold denial of Christ, and was plainly designed to do so; and when he thought thereon he wept. Every remembrance of past sins, even pardoned sins, renews the sorrow of a true penitent. Thou shalt be ashamed, when I am pacified towards thee. Secondly, Because it put him in fear lest his Master foresaw some further miscarriage of his, which would be as great a contradiction to this profession of love to him as the former was. “Surely,” thinks Peter, “my Master would not thus put me upon the rack if he did not see some cause for it. What would become of me if I should be again tempted?” Godly sorrow works carefulness and fear, 2Co_7:11.
(3.) Three times Christ committed the care of his flock to Peter: Feed my lambs; feed my sheep; feed my sheep.
[1.] Those whom Christ committed to Peter's care were his lambs and his sheep. The church of Christ is his flock, which he hath purchased with his own blood (Act_20:28), and he is the chief shepherd of it. In this flock some are lambs, young and tender and weak, others are sheep, grown to some strength and maturity. The Shepherd here takes care of both, and of the lambs first, for upon all occasions he showed a particular tenderness for them. He gathers the lambs in his arms, and carries them in his bosom. Isa_40:11.
[2.] The charge he gives him concerning them is to feed them. The word used in Joh_21:15, Joh_21:17, is boske, which strictly signifies to give them food; but the word used in Joh_21:16 is poimaine, which signifies more largely to do all the offices of a shepherd to them: “Feed the lambs with that which is proper for them, and the sheep likewise with food convenient. The lost sheep of the house of Israel, seek and feed them, and the other sheep also which are not of this fold.”
Note, It is the duty of all Christ's ministers to feed his lambs and sheep. Feed them, that is, teach them; for the doctrine of the gospel is spiritual food. Feed them, that is, “Lead them to the green pastures, presiding in their religious assemblies, and ministering all the ordinances to them. Feed them by personal application to their respective state and case; not only lay meat before them, but feed those with it that are wilful and will not, or weak and cannot feed themselves.”
When Christ ascended on high, he gave pastors, left his flock with those that loved him, and would take care of them for his sake.
[3.] But why did he give this charge particularly to Peter? Ask the advocates for the pope's supremacy, and they will tell you that Christ hereby designed to give to Peter, and therefore to his successors, and therefore to the bishops of Rome, an absolute dominion and headship over the whole Christian church as if a charge to serve the sheep gave a power to lord it over all the shepherds; whereas, it is plain, Peter himself never claimed such a power, nor did the other disciples ever own it in him. This charge given to Peter to preach the gospel is by a strange artifice made to support the usurpation of his pretended successors, that fleece the sheep, and, instead of feeding them, feed upon them. But the particular application to Peter here was designed, First, To restore him to his apostleship, now that he repented of his abjuration of it, and to renew his commission, both for his own satisfaction, and for the satisfaction of his brethren. A commission given to one convicted of a crime is supposed to amount to a pardon; no doubt, this commission given to Peter was an evidence that Christ was reconciled to him else he would never have reposed such a confidence in him. Of some that have deceived us we say, “Though we forgive them, we will never trust them;” but Christ, when he forgave Peter, trusted him with the most valuable treasure he had on earth.
Secondly, It was designed to quicken him to a diligent discharge of his office as an apostle. Peter was a man of a bold and zealous spirit, always forward to speak and act, and, lest he should be tempted to take upon him the directing of the shepherds, he is charged to feed the sheep, as he himself charges all the presbyters to do, and not to lord it over God's heritage, 1Pe_5:2, 1Pe_5:3. If he will be doing, let him do this, and pretend no further.
Thirdly, What Christ said to him he said to all his disciples; he charged them all, not only to be fishers of men (though that was said to Peter, Luk_5:10), by the conversion of sinners, but feeders of the flock, by the edification of saints." Matthew Henry