Following Jesus’ departure, it is important for Jesus’ followers to be confirmed as legitimate representatives of the message Jesus taught. This is done by Peter performing miracles, like Jesus did. Peter is careful to point out that what he is doing is being done through God’s power and not his own.
Christians can mess up in some big ways sometimes, but, like in this chapter, they can also accomplish some amazing things too. Miracles like healings or changed lives and entire communities transformed can happen, but these are done in God’s power. It’s important for Him to get the credit!