Peter was imprisoned again when King Herod began persecuting the church.But the high priest rose up, and all who were with him (that is, the party of the Sadducees), and filled with jealousy they arrested the apostles and put them in the public prison. But during the night an angel of the Lord opened the prison doors and brought them out, and said, “Go and stand in the temple and speak to the people all the words of this Life.” And when they heard this, they entered the temple at daybreak and began to teach.
Acts 5:17-21 ESV
Herod must have known of Peter’s previous release because he took precautions to make sure it didn’t happen again.About that time Herod the king laid violent hands on some who belonged to the church. He killed James the brother of John with the sword, and when he saw that it pleased the Jews, he proceeded to arrest Peter also.
Acts 12:1-3 ESV
Of course it is futile to try to thwart God’s will.And when he had seized him, he put him in prison, delivering him over to four squads of soldiers to guard him, intending after the Passover to bring him out to the people. So Peter was kept in prison, but earnest prayer for him was made to God by the church.
Now when Herod was about to bring him out, on that very night, Peter was sleeping between two soldiers, bound with two chains, and sentries before the door were guarding the prison.
Acts 12:4-6 ESV
When Herod found out that Peter had escaped he blamed the guards for failing to do their duty.And behold, an angel of the Lord stood next to him, and a light shone in the cell. He struck Peter on the side and woke him, saying, “Get up quickly.” And the chains fell off his hands.
And the angel said to him, “Dress yourself and put on your sandals.” And he did so.
And he said to him, “Wrap your cloak around you and follow me.” And he went out and followed him. He did not know that what was being done by the angel was real, but thought he was seeing a vision.
When they had passed the first and the second guard, they came to the iron gate leading into the city. It opened for them of its own accord, and they went out and went along one street, and immediately the angel left him.
Acts 12:7-10 ESV
Herod’s action was unfair. The guards had carried out their duties faithfully. There was no way they or anyone else could have prevented the angel from freeing Peter.Now when day came, there was no little disturbance among the soldiers over what had become of Peter. And after Herod searched for him and did not find him, he examined the sentries and ordered that they should be put to death.
Acts 12:18-19 ESV
Although the guards suffered injustice at the hands of Herod they had been given a priceless opportunity by God. They had spent time in the presence of a man who had been chosen by God to preach the gospel and I am certain that Peter took advantage of the opportunity to tell them the way of salvation. In a sense the men chained to Peter were just as much prisoners as he was; he couldn’t escape from prison and they couldn’t escape hearing the truth about God.
It is unlikely that they would have wanted to avoid listening to him. Guarding a prisoner is a boring job. Listening to Peter would have brought them some relief from the monotony even if they didn’t believe anything he said.
When they were listening to Peter they might have thought that what he was saying was just superstitious nonsense. It was something to help them pass the time but not something to take seriously. If they did feel this way the shock of his supernatural escape would have convinced them that what he had said was true.
God allowed the guards’ physical life to be taken from them but he also gave them the opportunity to receive eternal life which no one could take away. We will have to wait until we get to Heaven to find out whether or not they took advantage of that opportunity.