Unless the LORD of hosts had left unto us a very small remnant, we should have been as Sodom, and we should have been like unto Gomorrah.
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Augustine of Hippo
AD 430
Beware, O Christian, beware of pride. For though you are a follower of the saints, ascribe it always wholly to grace. That there should be any “remnant” in you, the grace of God has brought it to pass, not your own merits. - "Sermon 50 (100).4"
It was shown above what the prophetic word threatened against Jerusalem and Judah, not pertaining to the time of the Babylonian captivity but to the end of the Romans, when the remnant of the Jewish people were saved in the apostles, and three thousand believed in one day and five thousand on another, and the gospel was spread throughout the entire world. “The Lord of hosts” is our Latin translation, following Aquila, of the Hebrew “Lord of the Sabbath,” to which the Septuagint translators gave a double sense: either the Lord of powers or the Lord omnipotent. We also need to ask whether it was said about the Father or about the Son. But there is no doubt what we read in the twenty-third psalm: “Lift up your heads, gates, and be lifted up, eternal doors, and the king of glory will enter! Who is the king of glory? Lord of the sabbath.” The Lord of powers, he is the king of glory, referring to Christ, who ascended to heaven as victor after the triumph of the passion. And in another place ...
He here shows that even the few that were saved were not saved through their own resources. Even they would have perished and suffered like Sodom. That is, they would have been completely destroyed—for Sodom was destroyed root and branch, and not even the smallest seed remained. He means to say that they too would have been like those, except that God demonstrated his goodness to them and saved them by faith. This happened as well in their visible captivity in which most of them were taken captive and perished, in which only a few were saved. - "Homilies on Romans 16.10"
The Gentiles were utterly ignorant of the one true God and worshiped things they themselves made. The Jews and Samaritans, though, had been given the Word of God by the prophets and have always waited for the coming of Christ. However, they did not recognize him when he came, except for a few who were to be saved. - "First Apology 53.6"
Moreover, those teachers who believe that the descendants of Abraham according to the flesh will indeed share in the eternal kingdom, even if they are sinners without faith and disobedient to God, are deceiving themselves and you. These are speculations that the Scriptures demonstrate have absolutely no basis. If they did, Isaiah would not have said, “And except the Lord of hosts had left us seed, we had become as Sodom and Gomorrah.” - "Dialogue with Trypho 140.3.2"