What did Peter testify was not required for a Gentile to be saved?
According to the Acts 15 account, Peter testified that Gentile salvation did not require ascribing to Judaism, circumcision, keeping the Law of Moses, or even repentance and water baptism, because God saved the Gentile at Cornelius's house before Peter got that far.
Les teaches that Acts 15 records the great controversy between Peter and the eleven at Jerusalem and Paul and Barnabas over the Gentiles. The Pharisees said it was needful to circumcise Gentile believers and to keep the Law of Moses, but Paul refused to make that part of his message. Peter came to Paul's defense, remembering about fourteen years earlier at the house of Cornelius that God would save a Gentile without ascribing to Judaism, without repentance, and without water baptism. They were saved even before Peter got that far. The context also states the Gentiles were having salvation apart from Judaism, without circumcision, and without being commanded to keep the Law.