If there is one thing we should love about the early church it is their strength, courage, and dependence on God. It was a newly lit flame, and for them nothing had more value than the perfect cause of Christ, even if it cost them their own lives.
We see the apostle Peter, who walked alongside the Master, being one of the 12, having the privilege of belonging to the ministry of Jesus and seeing Him after His resurrection. In his first speech he spoke with great courage to the Jewish people, and now in Acts chapter 5 he also spoke with the same courage:
30 The God of our fathers raised up Jesus, whom ye slew and hanged on a tree.
31 Him hath God exalted with his right hand to be a Prince and a Saviour, for to give repentance to Israel, and forgiveness of sins.
32 And we are his witnesses of these things; and so is also the Holy Ghost, whom God hath given to them that obey him.
First of all, Peter, being an eyewitness to the ministry of Jesus, knew that they had murdered the true Son of God, and spared no time in blaming them for their crime.
Second, he continues to confirm the ministry of Jesus as Savior and who has the power to forgive sins. Do you know that the fact that Jesus can forgive sins was blasphemy for them? But what does it matter, Peter only wanted to expose the truth, without adding or removing.
Peter and the apostles knew that they were witnesses to Jesus, and the best way to demonstrate it was to speak the truth without fear, regardless of whether this cost them their lives. They knew they had a greater good, so their lives were not precious compared to the gospel ministry.