1-4 That's when King Herod got it into his head to go after some of the church members. He murdered James, John's brother. When he saw how much it raised his popularity ratings with the Jews, he arrested Peter—all this during Passover Week, mind you—and had him thrown in jail, putting four squads of four soldiers each to guard him. He was planning a public lynching after Passover. 5All the time that Peter was under heavy guard in the jailhouse, the church prayed for him most strenuously. 6Then the time came for Herod to bring him out for the kill. That night, even though shackled to two soldiers, one on either side, Peter slept like a baby. And there were guards at the door keeping their eyes on the place. Herod was taking no chances!
The message of Christ has always brought some form of conviction - some deal with that conviction with repentance, while others resist with all that is within. Herod was the Roman ruler over Judea - his "title" was Herod, but his "last name" was Agrippa. There are many men referred to as Herod or King Herod in the New Testament - keeping them all straight is hard. This is not the Herod who ordered babies killed after Jesus was born - fearful that the King of the Jews had been born as reported to him by the scholars of the day. Agrippa would have been his grandson. He was unusually liked by the Jews of the day because he showed them favor, supporting them in their religious pursuits.
As such, he was opposed to those that appeared to be doing or saying anything that was contrary to the Jewish laws and rabbinical teachings. Therefore, when the disciples and apostles were preaching a message of salvation and faith in Christ as the only way to have redemption from their sins, he sided with the Jewish members of the community to attempt to "shut them up" in the spreading of this message. He often used a sentence of time in jail as one of the means to silence them - causing them great distress through the time spent in jail, the beatings and other forms of torture that often went along with a term in jail.
It is Passover week once again, and he is knows Jerusalem will be filled with not only his Jewish supporters, but those that stood as their opposition - like James and Peter. James' fate was death - Peter was imprisoned with the intention that he would also know this same fate. The delay in accomplishing his plan was the Feast of Passover - in respect to his Jewish supporters, he deferred to bring the final blow to Peter until after the Passover celebration. News about how God was at work in the ministry of Peter must have reached Herod. Why else would he have four squads of four soldiers each to guard him around the clock? Why would he have had him shackled to two soldiers while he slept? I think Herod had heard the reports of the power of God in Peter's life and may have wanted to ensure his prisoner was still there come time for the lynching.
Herod is not the main character of this passage though - God is. Peter is really the secondary focus here - God's presence in his life and his ministry is preeminent. Peter is able to rest, sleeping soundly, because he is assured of the God in which he has placed his trust. Look also at the response of the other believers to the presumed "fate" of Peter - they made it a matter of unending prayer because they knew in whom they believed and were confident that God would intervene.
The "rest of the story", as Paul Harvey would say, is the "suddenness" of God's intervention. Peter could have been delivered from the hand of Herod at any time, but God chose the night before his scheduled death. An angel appears, waking him, telling him to dress and then escorts him out of the jail - free of the shackles, free of the guards, and past the secured iron gates guarding the city. The guards were oblivious to the intervention of God - Peter was wondering if he was dreaming - and the praying church would be suddenly elevated out of their spirit of petition into a spirit of praise.
When God is trusted, his intervention is certain. When God is elevated to preeminence in a person's life, his provision is certain. When God is foremost in the actions of a person's life, his protection is certain. Peter rested well, even in the midst of his most fearful night, because he knew the God he trusted had all in his control. We need to fear no man (nor woman) - they can do nothing apart from God's watchfulness over us. We need not to fear any bondage as permanent and unyielding to his touch - his touch is greater than anything that binds us. We need to not believe the threats of things which seem impossible to us - for all things are made possible when the Lord is Lord of our lives.