Paul writes to Gentile (non Jewish) believers a powerful warning which should drive us to gratitude and humility. He explains that for the present time, Israel has been set aside and salvation has come to the Gentiles (myself and likely you):
 But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree,  do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you.  Then you will say, “Branches were broken off so that I might be grafted in.”  That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear.  For if God did not spare the natural branches, neither will he spare you.  Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. (Romans 11:17-22 ESV)
This warning makes little sense to those who have no sense of wonder at the fact that a Gentile could be saved at all. It makes no sense to those who think God is obligated to save them.
In arrogant presumption, most modern Gentile people (including many church people) take God, for all practical intents and purposes, for granted. Our assumptions about God are not often blatantly stated, but they might be under many of our thoughts and statements. For example, we assume that we are God’s judges and that we will judge his word (is it accurate? Is it reliable?). We presume to judge whether Jesus is worthy of our devotion to him (will we choose to allow him to be our saviour?). As believers we talk about the Lordship of Christ in our lives as an option (will we make Christ Lord?). There are obvious problems with this sort of attitude.
The Gentile Problem: Here is one most people have likely not considered. Most Christians today, are Gentiles, and Gentiles have a specific problem. Paul writes in Ephesians 2, that as Gentiles we were born, “by nature, children of wrath” and “were at that time separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants and promise, having no hope and without God in the world ” (Eph. 2:3, 12).
The fact that we are born under wrath, is little discussed. Now we often talk about sin and its consequences, and rightly so. For example, “the wages of sin is death” (Rom. 6:23). And “the one who sins shall die” (Eze. 18:20). Yet back and behind our various sins, is an even greater problem. Humanity is under a divine sentence of death. Roman 5:12 explains: “sin came into the world through one man and death through sin, and so death spread to all men because all sinned”. In a nutshell, Adam, as our representative chose to declare war on God. This is much like the result of a US president, declaring war and the media noted that the US is at war with such a such a state. One man, represents the nation, and all the consequences that follow, follow upon the whole nation.
Because of this legal declaration of universal condemnation, a legal remedy must be found apart from the issue of our own individual sins. God in grace promised Adam and Eve that he would send a “redeemer”. But by Genesis 6, God found that he was “sorry that he had made man on the earth and it grieved him to his heart” (Gen 6:5). As a result he determined to apply justice and “blot out man whom I have created from the face of the ground” (v. 6).
But yet, God’s kindness and mercy is seen, in that he chose one man to restart the human race with a clean slate. That man was Noah, “Noah found grace in the eyes of the Lord” (Gen 6:8), and “Noah did… all that God commanded” (6:22). Unfortunately, after the great judgement of the flood and the clean break they had, all was not well. Noah became a drunkard (Gen 9:21), at least one of his sons became a notorious sinner (9:24-25), and within a few generations, the exact conditions of the fall were repeated and men set themselves up in direct rebellion against God (see Gen 9:7 and 11:4).
The Jewish Promise: God made a promise of redemption to one more individual in history, Abraham. He did not make this promise to any other person, or any other nation, but to him and his descendants God promised blessing and made with them “an everlasting covenant to be God to you and to you offspring after you” (Gen 17:7). The Gentiles united with Abraham and his descendants could then be “blessed” and those who opposed him and his descendants “cursed” (Gen 12:3). But to Abraham’s people, (Israel and those who formerly joined with them only) God promised, “the LORD your God will circumcise your heart and the heart of your offspring, so that you will love the LORD your god with all your heart and with all your soul, that you may live” (Deu. 30:6). In other words, God would supernaturally change them from rebels to saints.
From Abraham would come the redeemer who would restore God’s perfect rule on the world in Israel (Jeremiah 34:25-26) and be “numbered with the transgressors” ie the rebels “and make intercession for the transgressors” of Israel, when “his soul makes an offering for guilt” (Is 53:10-12). Thus when Jesus, this promised one was born, it was announced from Heaven that he would come and “save his people (that is Israel) from their sins” (Matthew 1:27). Jesus told the Samaritan halfbreed, “we worship what we know for salvation is from the Jews” (John 4:22) and instructed another Gentile, saying, “I was sent only to the lost sheep of the house of Israel” (Matthew 15:24).
The Gentile Promise: The Gentiles, in contrast have no part in any of this. Speaking of the Gentile nations the divine promise is: “the LORD is enraged against all the nations and furious against all their hosts; he has devoted them to destruction, he has given them for slaughter” (Is. 34:2). On them God says, “I will take vengeance, I will spare no one” (Is. 47:3). By nature we Gentiles are, we must remember “children of wrath” and “separated from Christ, alienated from the commonwealth of Israel and strangers to the covenants and promise, having no hope and without God in the world” (Eph. 2:12). being strangers from “the covenants of promise” Gentiles have no claim on God for redemption, and thus “no hope”.
The Rest of the story: Paul Harvey was famous for his radio story telling, in which he showed a seemingly insurmountable obstacle, and then revealing a new twist, he would declare “and now you know the rest of the story”. What is the rest of the story for Gentiles. How did the we come to be included in the promises to which we were strangers? How did the Gentiles come to have any part in God’s mercy? Without hope and without God, we could and can do absolutely nothing to reconcile with God. Thus it is that the greatest “but” in the Universe must enter into our minds. “But God” Ephesians 2:4 states, “being rich in mercy, because of the great love with which he loved us” (Gentiles and Jews) “even when we were dead in our trespasses” (state of and active engagement in rebelling against him), God “made us alive together with Christ–by grace you have been saved” (Eph 2:4-5).
The cost of Grace was immense. “in Christ Jesus you who once were far off” Gentiles “have been brought near” notice, “by the blood of Christ” (Eph. 2:13). Jesus told his disciples “I have other sheep, which are not of this fold” (John 10:16). The black sheep of creation, the Gentiles had a place in Christ’s plan.
In this plan, the violent and brutal death of Christ was necessary, to pay the penalty for Adam’s sin, and offer a gift, a gift of forgiveness and eternal life. But more than that, in a Gentile context, Christ died that he “might reconcile us both (Jew and Gentile) to God in one body through the cross, thereby killing hostility” (Eph 2:16).
Consider again the love of God and take to heart Paul’s warning: Now, considering both the awesome cost of our salvation, our natural just deserts and the fact that apart from God’s special act of including us in his covenants, to which he had not bound himself to us in any way but out of a heart of great love, how ought we to respond to that love? How humble ought we to be? How grateful? Understanding the truth, how could we take God for granted and act as if the most important and relevant being in our lives was due not our best, but our seconds, not our love but our tolerance, not our passion, but our bare duty?
How now can we take the warning of Romans 11:
…do not become proud, but fear.  For if God did not spare the natural branches, neither will he spare you.  Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness. Otherwise you too will be cut off. (Romans 11:120-22).