Final answer:
Peter stated that the promise of the Holy Spirit was for all whom God would call, implying that it was not just for the Jews but for the Gentiles and all who are far off, signifying a universal offer of salvation.
Step-by-step explanation:
Peter spoke about the promise of the Holy Spirit in the Book of Acts in the New Testament, which captures the early history of Christianity. According to Acts 2:39, Peter proclaimed that the Holy Spirit was promised to 'all whom the Lord our God will call' – not exclusive to a single ethnicity or group. In the context of that day, it meant that the promise was extended to the Jews, the Gentiles, and indeed 'all who are far off', encompassing every nation and people who would come to believe in Jesus Christ.
This was a significant shift from the idea that salvation was limited to the Jews, and it was a part of the larger Christian teaching that salvation and the gift of the Holy Spirit were universally available to all through faith in Jesus Christ.