The apostles and the brothers throughout Judea heard that the Gentiles also had received the word of God.
This is shocking news! Even though Jesus told His students to go into all the world and make students in every nation, at first they didn't understand what the Teacher meant by this!
Evidently, they mistakenly thought Jesus was telling them to go to the people of Israel who had been scattered and were now living in every nation. That’s why for some period of time everyone in the Christian Community was Jewish.
Now, in the home of a Gentile, Jesus miraculously shows Peter what He meant by every nation. Jesus gives the Holy Spirit to Cornelius and his household.
The circumcised (Jewish) believers who had come with Peter were astonished that the gift of the Holy Spirit had been poured out even on the Gentiles.
Understanding what has happened, Peter instructs Cornelius and his family to be baptized in water in the name of Jesus.
Returning to Jerusalem, Peter has some explaining to do - So when Peter went up to Jerusalem, the circumcised (Jewish) believers criticized him and said, “You went into the house of uncircumcised men and ate with them.”
Peter carefully recounts the whole story. They are convinced. If God has given the Holy Spirit to Gentiles, then the Good News of Jesus is assuredly for them also.
When they heard this, they had no further objections and praised God, saying, “So then, God has granted even the Gentiles repentance unto life.”
From the cradle of Judaism to the entire Gentile world! The Teacher Himself had said it. They would be His witnesses beginning in Jerusalem and Judea, then in Samaria and finally to the uttermost parts of the earth!