Peter and John left the temple grounds and went to the assembly of believers. They wanted to both share what had happened and be filled again to go out and do the work of the Messiah.
It was important that they share what had happened so all the rest would know what was going on and what to expect from the rulers. They could rejoice that they were able to preach the gospel directly to the leaders. Jesus had told them they would be taken before leaders and here it had happened. Now they had started the mission Jesus gave them.
They first praised God for his sovereignty and his plan. They remembered how God had been with them all a long. They praised God for his power and majesty and how they expected God to help them since it was his plan.
Instead of being afraid because of the threats of powerful men, they wanted God to prepare them to continue. They had been afraid before Pentecost, but now with the Holy Spirit filling and guiding them, they had the boldness and courage to be plain and forceful in preaching. They were so focused on their mission given by Jesus, they did not worry about what would happen to them. They wanted more power to continue rather than protection.
The reference to Psalm 2 showed that they expected there to be blow back. But they did not want to shirk their duty so they asked for boldness not security. They asked for what to say and that signs and wonders would be there. They knew that proclaiming God’s kingdom would need a display for people to really get it.
Jesus was the Son of God and they intended to follow where Jesus said to go. They asked for healing which was a large part of what Jesus did. They had regrouped and encouraged each other. Now they all could go out and keep on preaching, and casting out demons.