Peter is not healing the man in order to win an opportunity for preaching. He could not know beforehand that this healing would create an opportunity for preaching. He heals the man from a place of compassion.1 The Spirit has created a compassion in his heart (much like the compassion which Jesus had for people; see Matthew 9:35–38).
6 But Peter said, “I have no silver and gold, but what I do have I give to you. In the name of Jesus Christ of Nazareth, rise up and walk!”