Even though Peter has witnessed his fellow apostle James, the brother of John, put to death with a sword; even though it is the anniversary of Jesus' arrest, torture and crucifixion (the text notes that Peter's escape occurs during Passover week); one can see that Peter is living in the power of the resurrection. He is bound with heavy chains at the wrist, personally guarded by four soldiers, and peacefully sleeping in his cell.
An angel appears and lights up the cell. Peter is so sound asleep that the angel has to strike him on the side to wake him up. The text tells us that Peter thought he was experiencing a vision...as well he might. Peter had some pretty intense visions (see Acts 10). Still he knew enough to obey the angel's directions, so after his chains fall off (!) he gets up, gets dressed, and follows the angel past every sentry on guard.
One might think the guards were sleeping on the job, but these are Roman soldiers, four squads of four soldiers each, so they're only working six hour shifts, and they know the penalty for misplacing a prisoner...I doubt they were sleeping, but Peter and his angel guide pass right by without any interference.
The angel does not waste time or explain much, but simply gives orders and expects them to be fulfilled.He knows what Peter needs, where he needs to go, and how to get him there safely. He is a personal escort, sent by God to lead Peter to safety.
The angel leads Peter out through the city gate, which opens by itself for them. I don't think we're talking about a picket fence with loose hinges on the gate here. I'm no expert on these things, but I imagine opening the city gate was normally a job for more than one person. Here it opens as if it were a modern automatic door.
Shortly thereafter the angel disappears and Peter (finally) realizes it is not a dream, not a vision, but that he is really free. He knows just where to go - prayer meeting! And even though those attending the prayer meeting have been earnestly praying for his release, they don't believe it when he shows up on the doorstep. Talk about an answer to prayer! Poor Peter's standing on the doorstep, "Hey, guys! Let me in, quick!"
Peter's turn to disappear. When he is nowhere to be found the King orders the guards who lost him to pay the ultimate price. This, again, is reminiscent of the resurrection, except that the guards who let Jesus get away were spared death, rather they were paid to keep silent.
Why is Peter rescued where James was executed? This is a specific form of an age old question, "Why me, God?" The whole book of Job is full of this question, and God's answer is because He is God. He is sovereign. He knows. Peter still had work to do, people to meet, lessons to learn. James, evidently was ready to graduate, but only God knew their stories and how and when they would end.
We can pray and ask God for deliverance, protection, and angel guides. Many times they are probably there without us knowing it. Still we must remember that God's answer is sometimes "no" but He still knows what is best. Psalm 91 describes His desire to protect us, but also places the emphasis on relying on Him:
If you make the Most High your dwelling-
even the Lord, who is my refuge-
then no harm will befall you,
no disaster will come near your tent.
Psalm 91:9-10 (NIV)
