This part of Acts seems to move energetically and purposely through what transpired in Jerusalem before corruption from within and persecution from without forced many Christians out and thus ignited the explosion of Christian missionary work and the spread of the apostle's message. I get pumped just reading through it.
When you look at Peter’s words to the people and the temple authorities, you don’t see dry speeches. He doesn’t give doctrinal dissertations, though teachings are certainly contained in them. And he doesn’t give motivational speeches intended to encourage people to just be more socially active and live moral lives while quoting “Old Testament examples” here and there, though living a holy life is part of it. In Peter’s words you see him telling the climactic event of the grand epic that Moses and the Prophets were all leading up to, Jesus’ resurrection from the dead! Peter heals this man born crippled so that he can focus (the healing is called a sign) on telling the people and the temple authorities about what Jesus has done to restore all things (as he did this born crippled) and bring about promised the time of restoration.