"But on arriving at the jail, the officers did not find them there. So they went back and reported, 'We found the jail securely locked, with the guards standing at the doors; but when we opened them, we found no one inside.'" NIV translation
Isn't it awesome how God takes care of his people? Only He could take his people out of a locked jail cell and leave the captors wondering what had happened.
"On hearing this report, the captain of the temple guard and the chief priests were puzzled, wondering what would come of this." NIV translation
Now, they know that they have a big problem. They started to wonder how this was going to affect their power. Talk was going to get around about how the prisoners were miraculously released from the prison.
"Then someone came and said, 'Look! The men you put in jail are standing in the temple courts teaching the people.' At that, the captain went with his officers and brought the apostles. They did not use force, because they feared that the people would stone them." NIV translation
Isn't this interesting? The apostles were teaching the people about Jesus Christ and it was working. Notice how we are told in this passage that the officers did not use force because they were afraid that the people would stone them. The people did not have a problem with the teaching, it was the religious establishment. Sadly, we face many of the same type of struggles in the church today.
"Having brought the apostles, they made them appear before the Sanhedrin to be questioned by the high priest. 'We gave you strict orders not to teach in this name,' he said. 'Yet you have filled Jerusalem with your teaching and are determined to make us guilty of this man's blood.'" NIV translation
The high priest, instead of repenting, is trying to protect his reputation. If the apostles teaching that Jesus is the Messiah is true, then, it makes the religious establishment guilty of murder. You see, Jesus was basically put on trial and executed for saying that He was the Son of God. If it was true (which was demonstrated by his resurrection), then, he was falsely accused by the Sanhedrin therefore His blood would be on their hands. They were also afraid of riots and losing their power when the people learned of what had happened.