Luke 22:31 And the Lord said, Simon, Simon, behold, Satan hath desired to have you, that he may sift you as wheat:
To sift, to separate you, to cause you to be undone. Separated from hope, pushed through a screen making you many pieces to be blown away in the wind. Satan desires to utterly destroy you, as he would destroy Judas.
Luke 22:32 But I have prayed for thee, that thy faith fail not: and when thou art converted, strengthen thy brethren.
Already Jesus is interceding for his own. Peter was one of his own, Judas he knew to be a son of the devil, but Peter, though weak in the flesh, was protected by the prayers of Jesus. Haleluia!
John 17:8 For I have given unto them the words which thou gavest me; and they have received them, and have known surely that I came out from thee, and they have believed that thou didst send me.
John 17:9 I pray for them: I pray not for the world, but for them which thou hast given me; for they are thine.
It is being connected to Jesus that is our strength. Peter did not have the permanent indwelling of the Holy Spirit, for He had not yet come.
Luke 22:33 And he said unto him, Lord, I am ready to go with thee, both into prison, and to death.
Peter with all sincerity makes a promise, a promise he could not keep. It is the pride of self, boasting of what it plans to do, but unable to fulfill the promise. We should not make promises we cannot keep. The pride of man boasts many things, but the heart is deceitful and the flesh seeks it's own good first. Think of the man Jesus Christ, not just a man but a man of God's Spirit, the son of God. He kept his Father's will.
Rom 5:6 For when we were yet without strength, in due time Christ died for the ungodly.
Rom 5:7 For scarcely for a righteous man will one die: yet peradventure for a good man some would even dare to die.
Rom 5:8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us.
Luke 22:34 And he said, I tell thee, Peter, the cock shall not crow this day, before that thou shalt thrice deny that thou knowest me.
Jesus said, " when thou art converted, strengthen thy brethren." Isn't believing in Jesus enough? Peter believed, buthe needed God's strength within. He needed the Holy Spirit. At Pentecost Peter was filled, converted, a new man in Christ Jesus with Holy Ghost boldness. When he spoke, people were convicted of sins. Peter spoke after Pentecost to the Jews.
Acts 2:36 Therefore let all the house of Israel know assuredly, that God hath made that same Jesus, whom ye have crucified, both Lord and Christ.
Acts 2:37 Now when they heard this, they were pricked in their heart, and said unto Peter and to the rest of the apostles, Men and brethren, what shall we do?
Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins, and ye shall receive the gift of the Holy Ghost.
Acts 2:39 For the promise is unto you, and to your children, and to all that are afar off, even as many as the Lord our God shall call.
The flesh man Peter would deny the Lord three times. God looks beyond our failings to our callings in him. He sees us as victorious in Christ Jesus, being the light of the world.