Peter, through the power of the Spirit and by the authority given to him by Jesus, was a channel of blessing to this broken man. It wasn't his power, but the power of Jesus. Like the blind man Jesus healed in Matthew 21, this man was healed so that the works of God might be displayed in him, pointing to the Messianic authority of Jesus. In Christ, God gives people so much more than they expect or deserve. Notice the progression of joy in [v.8] – the man stood firm, began to walk, then moved into an all-out sprint into the presence of God, leaping and praising Him all the way.