After Christ bequeathed to his disciples the kingdom of God, Peter saw himself as a prime minister sitting at the right hand of the Son, and reigning with him forever. He relied on his own experience, mighty power, courageous faith, and revealed testimony; but did not see the hidden movements of the invisible world to cause the apostles to fall.
The divine wisdom permits Satan to appear before God to accuse the saints, and to take a permission to test them. This testing is like sifting the believer several times with a course country sieve to separate the good seed from the tares. Similarly, the evil one took permission from God to sift the twelve disciples mercilessly in order to shake them, and prove that they were unqualified for the apostolic office. Are you aware of the striving between God and Satan for us in the backstage of the universe? The devil is determined to destroy you. So what are you: tares, flour, or barley?
Jesus addressed Simon twice using his old name, to warn him, and to show him that his old hot, coward temper was still in him. Christ did not only foresee Peter’s fall, but also prayed and mediated to God for him, asking God to strengthen his faith. This intimates that no man lives from his own strength, but his faith, love, and hope are a result of Christ’s intercession. Therefore your faith is a grace. It is not your own work.
Jesus looked more at the future. He foresaw Peter’s regret and the outpouring of the Holy Spirit in him. He also foresaw the unsuccessful denier rising boldly, not by his own strength, but guided by the Holy Spirit, and announcing fearlessly God’s truths in the gospel. This was the radical conversion in Peter’s life: that he knew how he was nothing in himself, coward, and sinful; but Christ’s grace alone purified him, and empowered him to successful testimony of Christ’s redemption. Thus he who was self-conceited and unqualified, became a broken comforter to many, lifting up the church in God’s power to the living faith founded on true repentance. He confessed in the first apostolic council: "We believe that we shall be saved through the grace of the Lord Jesus Christ and not through our own futile strength.
Then when they were in the upper room, it did not occur to Peter that he might fall or be converted, but he claimed that he was ready even to die with Christ in his struggle for authority. Jesus looked at him sadly, and told him who had testified that Jesus is the Christ, the Son of God, that he would be deeply drowned that he would openly deny him thrice, claiming that he did not know or ever saw the Savior of the world, and that the cock-crowing would prove to him that Christ is the merciful Omniscient who had forewarned him and put him on his guard.