Final answer:
Peter speaks to the crowd after healing the beggar to demonstrate Jesus' power and divinity, and to reinforce the legitimacy of His mission and teachings.
Step-by-step explanation:
After healing the beggar, Peter speaks to the crowd to affirm the power and the divinity of Jesus Christ through the miracle that has just occurred. The healings and miracles performed in the name of Christ were critical for the early Christian community to demonstrate the truth of Jesus' teachings and to spread their faith among the people.
In the specific instance of Peter and the beggar, it showcases an act of faith and the benevolence of the Christian doctrine, which Peter then uses to address the crowd, reinforcing the legitimacy of Jesus' divine mission and the reasons why they should follow His teachings.