As the story begins Peter holds the traditional understanding that a person had to essentially convert to Judaism before converting to Christianity. By the end of the story his understanding of how God is working is dramatically changed. Verse 45 is a key verse.
"The circumcised believers who had come with Peter were astonished that the gift of the
Holy Spirit had been poured out even on the Gentiles."
Did you notice that last phrase? "Even on the Gentiles." You can hear in this the way in which the circumcised believers felt about the Gentiles. It reminds me of John 1 when Nathaniel asks Phillip, "Can anything good come from Nazareth?" The nerve of God! To go beyond our understanding, to go beyond our expectations, and bless someone who is different from me with the Holy Spirit! Yes, God blessed even the Gentiles.
Which group of people do we think of today as Peter and the others thought of as the Gentiles? What country, or gender, or economic status, or political party, or religion, or denomination, or sexual orientation, or skin color, or ... do you (we) assume God will not work through?
I pray that God surprises us again and again with the ones that God chooses to bless.