I want especially to focus on the words of Peter's sermon:
"You that are Israelites, listen to what I have to say: Jesus of Nazareth, a man attested to you by God with deeds of power, wonders, and signs that God did through him among you, as you yourselves know—this man, handed over to you according to the definite plan and foreknowledge of God, you crucified and killed by the hands of those outside the law. But God raised him up, having freed him from death, because it was impossible for him to be held in its power." ...
Now when they heard this, they were cut to the heart and said to Peter and to the other apostles, "Brothers, what should we do?" Peter said to them, "Repent, and be baptized every one of you in the name of Jesus Christ so that your sins may be forgiven; and you will receive the gift of the Holy Spirit. For the promise is for you, for your children, and for all who are far away, everyone whom the Lord our God calls to him." (Acts 2:22-4, 37-39).
What immediately sticks out to me is the repeated use of the personal pronoun: you Israelites; a man attested to you; you yourselves know; handed over to you; you crucified and killed; be baptized every one of you; the promise is for you. Peter is emphasizing in a very pointed manner the fact that his audience were in every implicated in what happened to Jesus of Nazareth -- his rejection, his crucifixion, etc.At the same time, however, these very same persons are also the recipients of some tremendous promises, namely the promise of the Holy Spirit!
This is what is so impressive to me: that the very persons who killed the Son of God are also the intended inheritors of the promised Holy Spirit. That is the mind-boggling majesty of the grace of God, that those who victimize him are the same persons he wishes to bless and to restore to him. He doesn't oppose them, he doesn't want them to be destroyed, but rather he wishes to do them good. More than that, because it is through the death of Christ that we are reconciled to God, a death in which they played an integral part, God evidently wishes to use their very evil to do them the greatest possible favor -- restoring them to their Creator for their salvation!
Imagine you love some person, but this person hates you. Not only does he hate you, but if you were to attempt to strike up a friendship with this person, he will certainly harm you. Would you risk your life in order to accomplish friendship with a person who hates you, who wants nothing to do with you as things stand now? Yet God not only wishes to strike up friendship with his enemies, but he is willing to do so at extreme cost to himself, and willing to use his own victimization as the means by which this friendship is sealed and made possible.
I think this scene is even more impressive if we think about what it is exactly the descent of the Holy Spirit accomplishes in us. To this end, let us look at this verse from Paul's letter to the Romans:
For all who are led by the Spirit of God are children of God. For you did not receive a spirit of slavery to fall back into fear, but you have received a spirit of adoption. When we cry, “Abba! Father!” it is that very Spirit bearing witness with our spirit that we are children of God, and if children, then heirs, heirs of God and joint heirs with Christ—if, in fact, we suffer with him so that we may also be glorified with him (Rom 8:14-17).
Notice what the Spirit does. Through the Spirit, we are made children of God. Though Christ is the only-begotten Son of God, we become united to him and are in this way adopted by God, through the activity of the Holy Spirit. And this same Spirit convinces us that we occupy by grace the same position that Christ does by nature -- that of children of God. Through the Spirit, we are made children of God alongside Christ, and together with Christ, in the Spirit, we worship the Father and dedicate our whole lives to him.
We can see from this, then, that in a sense, the Spirit of God makes us a part of the family of God. Pentecost therefore represents the extreme hospitality of God: his willingness to welcome into his own family the very persons who harmed his Son.
Imagine that you have a daughter who loves a certain boy very much, but this boy is very bad and only ever makes fun of her. One day, when she approaches him and makes her love for him known and plainly stated, he responds by harming her: he pushes her into the mud, spits on her, and walks off laughing with his friends. What would your opinion be of the boy? Would you wish that boy to marry your daughter? If later in his life, he changed his mind and decided that he liked her, would you even entertain the thought of receiving him into your house? Or would you sooner tell your daughter, "Remember what he did to you! You deserve much better than him; I won't allow it"?
We are not very hospitable. We hold grudges and don't forget what others did to us, or to the ones we love. But God is not like that. At Pentecost, through the sermon of Peter, God shows that the very persons who rejected his Son are the ones he wishes to bring into his family, through baptism and the Holy Spirit. God's hospitality is extreme: he will not give up until we are made willing and worthy guests of his household, and he will meet us at every step of the way to see that we are not without the necessary help to accomplish this. Through the gift of the Holy Spirit, God wishes to adopt and to welcome into his family the very persons who previously hated him and wished his Son only evil. That is how generous God is!
Who can remain in servile fear of a God such as this? Who can keep from loving the very God which welcomes into his family persons who otherwise wanted to do him harm? They show that they hated God because they hated his Son who makes him known. Yet in spite of this, God's tremendous power and omnipotence is his ability to turn his enemies into friends, and strangers and aliens and orphans into sons. That is what we learn at Pentecost: the great power of the generosity of God to give the Holy Spirit.