Acts 4 is a witness to the missional beliefs of Peter and the earliest Christians, and to helps u in this reading, we are reading The Acts of the Apostles (Abingdon New Testament Commentaries). Peter (and John) heal a man; the authorities are overwhelmed by the response; they tell them to knock it off; Peter won’t stop telling the story of God’s saving power. The community is reshaped by the witness to the resurrection, by the opposition they are experiencing, and by the new-found courage that emerges. They are driven to the Scriptures to understand the events. Acts 4:23-31:

 On their release,
Peter and John went back to their own people and reported all that the
chief priests and elders had said to them. When
they heard this, they raised their voices together in prayer to God.
“Sovereign Lord,” they said, “you made the heaven and the earth and the
sea, and everything in them. You spoke by the Holy Spirit through the mouth of your servant, our father David:
   ” ‘Why do the nations rage
      and the peoples plot in vain?
 The kings of the earth take their stand
      and the rulers gather together
      against the Lord
      and against his Anointed One. Indeed Herod and Pontius Pilate met together with the Gentiles and the people of Israel in this city to conspire against your holy servant Jesus, whom you anointed. They did what your power and will had decided beforehand should happen. Now, Lord, consider their threats and enable your servants to speak your word with great boldness. Stretch out your hand to heal and perform miraculous signs and wonders through the name of your holy servant Jesus.”After
they prayed, the place where they were meeting was shaken. And they
were all filled with the Holy Spirit and spoke the word of God boldly.

Missional work is Scripture-shaped work, and that is seen in how the early believers soak themselves in Scripture to “interpret” what has happened. The creator is in control of the cosmos; the opposition to the gospel of Jesus is opposition to Jesus himself; because God is in control, the believers go to God and ask God to move amongst them as a witness to the truth of the gospel. That happens in miracle/power as well as word. (There is plenty of missional theology in that previous paragraph.)

How does this manifest itself? Part of that is in our next passage… tomorrow.