Why were the Jewish believers astonished at Cornelius's house?
The believing Jews were astonished because Gentiles were hearing a salvation message and believing it. They had recognized Jesus as the Christ, but they did not expect God to save Gentiles in this manner. The Holy Spirit fell on the Gentiles, and they spoke other languages as proof.
Les explains that the believing Jews, called "they of the circumcision," were utterly astonished that Gentiles were hearing a salvation message and believing it. These Jews had recognized Jesus as the Christ, like Peter. Les points out that there were six men who came with Peter, seven total, and God proved He was doing something totally different by having these Gentiles speak other languages. This occurred in the house of Cornelius, a Roman officer, not a great Colosseum.
And they of the circumcision which believed were astonished, as many as came with Peter, because that on the Gentiles also was poured out the gift of the Holy Ghost.
More Questions
How many Jews went with Peter to Cornelius, and who were the ones astonished?
According to Acts 11, six Jews went with Peter, so the seven Jews of the circumcision who believed were astonished at what happened.
Who were the circumcised believers that were astonished in Acts 10:45?
The circumcised believers who were astonished in Acts 10:45 were the believing Jews who came with Peter from Joppa—six Jews plus Peter, making seven in all.
Was Cornelius the first Gentile to be saved?
Gentiles had not been saved during the previous six, seven, or eight years — this was the first instance of Gentile salvation.