The gospel that my great great great great great great grandfather would have been saved and sanctified to God?

It depends on where your "great great great great great great grandfather" lived. If he had lived in India in the first century he would have known the gospel of St. Thomas, who founded the Indian Orthodox Church. And the baptism of Thomas would have been the same as the baptism of Paul because, as we know, "there is only one Lord one faith and "ONE BAPTISM" ".