Were proselytes like the Ethiopian eunuch saved before Philip explained salvation to them?
No. Most proselytes never really had salvation; they had religion only. The Ethiopian eunuch had been to Jerusalem to worship, yet on his way back to Ethiopia, Philip led him to salvation; he had not been saved beforehand. He was a proselyte without salvation.
Les explains that there were some proselytes, but most proselytes never really had salvation; they had religion, but they did not have salvation. He points to the Ethiopian eunuch in Acts chapter 8 as the witness: he was religious, had been to Jerusalem to worship at one of the feast days, but on his way back to Ethiopia, Philip led him to the place of salvation. Les says he had not been saved; he was a proselyte, but he did not have salvation. This contrasts with the Jewish believers with Peter who were astonished that Gentiles could be saved, because Gentile salvation had not happened before in their understanding.