During the Passover meal on the night before He was crucified, Jesus predicted that Peter would deny Him that very night, not once but three times (Luke 22:34). Before predicting this, Jesus explained to Peter that Satan had asked God to allow him to sift all of the disciples like wheat (Luke 22:31). Satan's goal was to cause the disciples to stumble, to fall away from Jesus and from their faith. I'd like to take a bit of poetic license here and imagine the scene in which Satan approached God with his request.
The throne room was filled with the angels of God, each one assuming a posture of reverence and awe as they stood in the presence of the Lord. Suddenly, from the back of the room, there was a great commotion as a dark presence pushed through the angel assembly and made its way to the front of the room. Just before the presence reached the front of the room, its path was blocked by Michael, the archangel.
"Stop right there, evil one!" said Michael. "What are you doing here?"
"Peace, Michael," said a voice from the throne. "Let him through."
Michael stepped aside and let Satan approach the throne.
"Where have you come from, Satan?" asked the Lord.
Satan responded, "Oh, I've been roaming around the earth, just going back and forth, from here to there, looking for someone to--"
"What is it you want?" the Lord thundered.
"I was wondering if you would see fit to allow me to sift those followers of your Son's like wheat. I just know that they will turn against Him. I mean You, of all people, should know how fickle they are and--"
"Silence!" said the Lord. "Very well, do as you wish. But see to it that you don't lay a finger on any of them."
Satan grinned, then turned and left the presence of the Lord.
Satan did get his way. He placed doubt and fear in the hearts and minds of the disciples. As Jesus predicted, Peter denied Jesus three times that night. But that's not the end of the story. When Jesus told Peter of Satan's request, He also said that He had prayed for Peter. His prayer was that Peter's faith would not fail. And, although Jesus knew that Peter would fall away, He also knew that Peter would turn back. He instructed Peter that, when he did turn back, he was to strengthen his brothers (Luke 22:32).
Peter did turn back. What Satan intended for evil, God used for good (Genesis 50:20). In 1 Peter 5:8-9, Peter gives us some of the best advice for dealing with our enemy, the devil. Peter's experience with the schemes of Satan in his own life gave him the knowledge he needed to be able to tell us that, in order to resist Satan, we must be alert. Satan will do whatever he can to shatter our faith and destroy our salvation. We need to resist him, and we can do this by standing firm in our faith. We need to hold on to our faith in Christ because it has the power to quench the fiery darts that Satan sends our way. Our faith is a shield that will keep us safe from the enemy's attacks. (Ephesians 6:16).