After the man was healed (see Acts 3:1-10), he joined Peter and John and climbs the steps into the temple courts, and as they did this, many people were amazed at the sight of the familiar man walking along, for they all knew him as the cripple who begged near the entrance to the temple. As you might expect, a fairly large crowd of people began to gather there seeking understanding of what had happened.
Seeing the awesome opportunity, Peter began to speak to the crowd. It would seem that Peter’s first thought was to interpret these events for his fellow Jews who were in a state of wonder, so he plainly told them that it was the God of Israel, not Peter, not John, who had done this amazing thing to glorify His servant Jesus, for it is only in the name of Jesus that such a thing could take place (3:12-13a). Isn’t this an interesting, not to mention telling, distinction between the Apostles and a fair number of modern day “healers”?
As a part of making this point, Peter once again pointed out that this Jesus to whom he was referring is the very same man that many in the crowd had participated in having crucified, and that they knew perfectly well who he was talking about (3:13b-15). In this statement, Peter also slipped in the fact that even though the people had participated in Jesus’ demise, He also rose from the grave, and that both Peter and John were eyewitnesses of that fact.