In these passages is the account of more and more Jews being converted to believe in Jesus. These people witnessed the Apostles’ powers to heal people of sickness and cast out demons.
The Apostles had great credibility in preaching Jesus, and the people believed in Jesus. The church was growing rapidly because of the Apostles’ powers and persuasion.
Today we do not have Apostles who can heal. But we do have the Bible which tells of their healing and details their experiences with Jesus. The Bible is essential to our walk toward salvation. We cannot know Jesus without the Bible. We cannot rightly believe in Jesus without the Bible.