Perhaps you are someone who likes to look through the remnant bin at the local cloth store. After people have bought a certain number of yards of cloth from a bolt, there is often a little bit left, a remnant. The store takes it off of the cardboard it’s wrapped around, folds it up into a little piece, and puts it with other small pieces into a bin in an aisle. What’s a remnant good for? A few crafty people with vision know. Little crafts, little clothes for little people, decorative parts of a pattern—remnants are very useful to someone with skill.
When Paul mentions a remnant in Romans 11:5, he is picking up a theme of the pre-exilic and post-exilic Old Testament prophets. “So too, at the present time there is a remnant chosen by grace.”
In Isaiah’s language, the remnant is the group of Israelites who remain after the Assyrian invasion of Tiglath Pileser III (Isaiah 10:20–22). They will have learned to rely on the Lord, not on political leaders, and they will be the group of people brought back in the future to the land of Israel (Isaiah 11:11–16). After the exile, Ezra, Nehemiah, Haggai, and Zechariah all refer to those who have returned from Babylon as the remnant.
Isaiah 11 has the remnant brought back from more places than Babylon, so it is not a surprise that Paul looks at all of the Jewish people around the Mediterranean coming to faith in Jesus as a fulfillment of Isaiah’s prophecy even before Judgment Day. What would such small groups of people, scattered and weak, be good for? The Lord is skillful enough to know what to do with them.
How did they get chosen by God to come to faith in Jesus? Paul assures his readers that they had done nothing to deserve it. It was by grace, and if any works were involved, then grace would no longer be grace. The Lord of the universe reaching into the bin of the human population knows what he is doing, and he can turn a remnant from disobedient and obstinate people into something wonderful.
But I ask: Did they not hear? Of course they did: "Their voice has gone out into all the earth, their words to the ends of the world." 19 Again I ask: Did Israel not understand? First, Moses says, "I will make you envious by those who are not a nation; I will make you angry by a nation that has no understanding." 20 And Isaiah boldly says, "I was found by those who did not seek me; I revealed myself to those who did not ask for me." 21 But concerning Israel he says, "All day long I have held out my hands to a disobedient and obstinate people." I ask then: Did God reject his people? By no means! I am an Israelite myself, a descendant of Abraham, from the tribe of Benjamin. 2 God did not reject his people, whom he foreknew. Don't you know what the Scripture says in the passage about Elijah-- how he appealed to God against Israel: 3 "Lord, they have killed your prophets and torn down your altars; I am the only one left, and they are trying to kill me"? 4 And what was God's answer to him? "I have reserved for myself seven thousand who have not bowed the knee to Baal." 5 So too, at the present time there is a remnant chosen by grace. 6 And if by grace, then it is no longer by works; if it were, grace would no longer be grace. Romans 10:18-11:6