As God had promised, The Holy Spirit was poured out on the believers gathered for the Pentecost feast. Its initial effect was experienced by well over one hundred believers, including the Apostles, who were given insight to the scriptures and the ability to speak in foreign languages.
Acts 2:9-12 9. Parthians, Medes and Elamites; residents of Mesopotamia, Judea and Cappadocia, Pontus and Asia, 10. Phrygia and Pamphylia, Egypt and the parts of Libya near Cyrene; visitors from Rome 11. (both Jews and converts to Judaism); Cretans and Arabs--we hear them declaring the wonders of God in our own tongues!" 12. Amazed and perplexed, they asked one another, "What does this mean?"
Some even accused the affected of being drunk, but Peter, with his new-found understanding of the scripture, knew what was happening.
Acts 2:14-15 14. Then Peter stood up with the Eleven, raised his voice and addressed the crowd: "Fellow Jews and all of you who live in Jerusalem, let me explain this to you; listen carefully to what I say. 15. These men are not drunk, as you suppose. It's only nine in the morning!
Filled with the Spirit, Peter goes on to to preach the central tenets of evangelical Christianity, the gospel of Jesus Christ. Peter is addressing a large crowd and authoritatively breaks down the event surrounding the death, burial, resurrection, and exaltation of Jesus. He quotes Joel and Psalms and does so effectively.
Acts 2:40-41 40. With many other words he warned them; and he pleaded with them, "Save yourselves from this corrupt generation." 41. Those who accepted his message were baptized, and about three thousand were added to their number that day.
Like Stephen's speech to the Sanhedrin in chapter seven, Peter's address to the crowd in chapter two is supernaturally good. It is in verses 14-41 and reminds me of what Jesus had told the Apostles in Matthew.
Matthew 10:19-20 19. But when they arrest you, do not worry about what to say or how to say it. At that time you will be given what to say, 20. for it will not be you speaking, but the Spirit of your Father speaking through you.
At the tail end of chapter two, there is an odd account of the new believer's lifestyle. It's odd because is seems out of place in the narrative. Here it is.
Acts 2:42-47 42. They devoted themselves to the apostles' teaching and to the fellowship, to the breaking of bread and to prayer. 43. Everyone was filled with awe, and many wonders and miraculous signs were done by the apostles. 44. All the believers were together and had everything in common. 45. Selling their possessions and goods, they gave to anyone as he had need. 46. Every day they continued to meet together in the temple courts. They broke bread in their homes and ate together with glad and sincere hearts, 47. praising God and enjoying the favor of all the people. And the Lord added to their number daily those who were being saved.
I personally think this passage suffers a great deal of abuse, so let me pile on a little more. I've heard people use this section to prove that we are supposed to meet in homes instead of churches. Every day. It has been said this proves that we are supposed to live with some kind of communal social structure where we all share a toothbrush. I have also heard a sermon citing this scripture as a mandate to give all of our possessions to the church and have the church take care of us in return. What could go wrong?
So then, why did Luke include this passage? Because God's new church was finally behaving as God had intended the Israelites to behave. The Holy Spirit now resides within the believers and as a result they are reacting with the charity and kindness that the Jews were supposed to show each other and the world around them. In Deuteronomy, Moses had directed the Israelites to be a light to the world and to be especially good to one another.
Deuteronomy 14:2 for you are a people holy to the Lord your God. Out of all the peoples on the face of the earth, the Lord has chosen you to be his treasured possession.
Deuteronomy 14:28-29 28. At the end of every three years, bring all the tithes of that year's produce and store it in your towns, 29. so that the Levites (who have no allotment or inheritance of their own) and the aliens, the fatherless and the widows who live in your towns may come and eat and be satisfied, and so that the Lord your God may bless you in all the work of your hands.
Deuteronomy 15:1 At the end of every seven years you must cancel debts.**
Deuteronomy 15:7-8 7. If there is a poor man among your brothers in any of the towns of the land that the Lord your God is giving you, do not be hardhearted or tightfisted toward your poor brother. 8. Rather be openhanded and freely lend him whatever he needs.
Deuteronomy 15:11 There will always be poor people in the land. Therefore I command you to be openhanded toward your brothers and toward the poor and needy in your land.
Deuteronomy 15:12-15 12. If a fellow Hebrew, a man or a woman, sells himself to you and serves you six years, in the seventh year you must let him go free. 13. And when you release him, do not send him away empty-handed. 14. Supply him liberally from your flock, your threshing floor and your winepress. Give to him as the Lord your God has blessed you. 15. Remember that you were slaves in Egypt and the Lord your God redeemed you. That is why I give you this command today.
** I like this one. They could still require payment from foreigners, but they had to cancel debts to each other every seven years. Moses closes the inevitable loophole in verse 9: Be careful not to harbor this wicked thought: "The seventh year, the year for canceling debts, is near," so that you do not show ill will toward your needy brother and give him nothing. He may then appeal to the Lord against you, and you will be found guilty of sin.