What does Acts 10:8 mean?

In the Roman religion, the gods worshipped weren't edifying. The pantheon of Roman gods was derived from the violent, capricious, and hyper-sexualized Greek gods. There were also local, ancient gods. And everyone was required to worship the emperor. Jews were generally the exception as occupying Roman forces discovered how rebellious the Jews could be when forced to abandon their singular, invisible God. Gentiles who were disillusioned by gods that never seemed satisfied sometimes dabbled with the mystical Jewish God who had no form.

Cornelius is a Roman centurion in charge of a cohort of soldiers in the Judean/Samaritan capital of Caesarea Maritima. He doesn't dabble with the Jewish God, he fully worships Him, earning the title "God-fearer." In honor of his faithful devotion, God sends him an angel who tells him to send for Peter in Joppa. Cornelius does so, sending two servants and one of the soldiers in his command who also worships God (Acts 10:1–7).

The next day, Peter will pray on the rooftop of Simon the tanner in Joppa. God will give him a vision, ostensibly affirming His teaching in Mark 7:19 that revoked the kosher food restrictions given in the Mosaic law. When Cornelius' messengers arrive, Peter realizes the vision means something much greater: Jesus is coming to the Gentiles (Acts 10:9–23). The realization will rock the expectations of the Jewish Jesus-followers, but it will set the stage for the ministry of the apostle Paul and fulfill the promise God made to Abraham that the world would be blessed through him (Genesis 12:3).