In Isaiah 52:13-53:12, the prophet spoke of God's servant who would be despised, rejected, esteemed not, wounded for our transgressions, oppressed and afflicted. Through Isaiah, God spoke of his servant as the righteous one who shall bear their iniquities and who bore the sin of many and makes intercession for the transgressors. In the ultimate fulfillment of the prophecy, Isaiah wrote in 52:13 that the servant shall act wisely and shall be high and lifted up and shall be exalted.
The Jewish people had been looking for hundreds of years for this “Servant” mentioned by Isaiah to free them from foreign oppression. Peter was using this familiar passage to show them that they had actually put Him to death. The nation of Israel had been looking for the lion that would free them from the crushing boot of the Romans and missed the Lamb. While Isaiah wrote of Jesus coming as the sacrificial lamb in his first coming, he also wrote about the ultimate fulfillment of the prophecy in the second coming of Jesus.
Isaiah 53:12 says of Jesus, "I will divide him a portion with the many, and he shall divide the spoil with the strong." Jesus the Lord of Lords and King of Kings will be exalted and return like a conquering general and in that second coming He will share with believers in His name the benefits of that exaltation.
Peter is telling the crowd that the Jesus they killed, the Author of Life is the key to being freed from captivity. He uses the limiting physical captivity of the lame man and the miracle derived from faith in Jesus' name as the prepared ground for presenting the gospel message and the freedom from the captivity of sin it offers. We should look for prepared ground today and do likewise.