13 Now I am speaking to you Gentiles. Inasmuch then as I am an apostle to the Gentiles, I magnify my ministry 14 in order somehow to make my fellow Jews jealous and thus save some of them. 15 For if their rejection means the reconciliation of the world, what will their acceptance mean but life from the dead? 16 If the dough offered as firstfruits is holy, so is the whole lump, and if the root is holy, so are the branches. 17 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, 18 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. 19 Then you will say, “Branches were broken off so that I might be grafted in.” 20 That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but fear. 21 For if God did not spare the natural branches, neither will he spare you. 22 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. 23 And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again. 24 For if you were cut from what is by nature a wild olive tree, and grafted, contrary to nature, into a cultivated olive tree, how much more will these, the natural branches, be grafted back into their own olive tree. (Romans 11:12-24 (ESV)
“Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. 5 I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing.” (John 15:4-5 (ESV)
I’m sure my friend Dr. Steven Hein picked up the term from somewhere, but I first heard it from him, “The Botanical Model of Sanctification”. It’s as Bo Giertz says, from a holy root grows a holy tree. We have been grafted into a holy tree. It’s really a funny thing. Again, God turns the whole world upside down. No one does this! No one takes fox grape branches and grafts them into a Pinot Noir vine. It’s the other way around. You take a branch from the fruit tree or vine that you enjoy, and you graft it onto a wild vine or Tree that would otherwise be a weed. Weeds always grow better than anything you would like to see grow, they just seem to have better root systems. But for some reason, the God takes the branches from what would be weeds and grafts them onto his root, and they produce the fruit he wants. The fruit is made holy because of the vine, and the vine is Christ. He cut the other branches off so that he could graft the gentiles in. It’s his vineyard, his olive tree. He gets the fruit he wants and the fruit is you. We abide in him through faith. It is unbelief that causes a branch to be broken off. So we remain in him by faith, and the sap that sustains faith is the gospel and the sacraments, not the fruit.
The tendency is to look at the fruit rather than the vine. Perhaps we are afraid that if we don’t produce the fruit that God wants he will break off the branch. But it is precisely when we begin trying to produce different fruit that we lose hope and break faith. If you graft a branch of fox grapes onto a Pinot Noir vine, you will get fox grapes. They don’t look as nice, and depending on your personal taste, they don’t taste as good either. But some people like them. Perhaps, given new soil and a stronger more established vine the fox grapes will be bigger, better, bolder, but they will still be fox grapes, and the fox grapes looking over at the pinot noir grapes will be jealous, and human nature what it is, the pinot noir grapes will be jealous of the fox grapes. And so one becomes jealous of another’s sacrifice, and it isn’t Able that is killed, but Cain who loses faith and murders, a much worse death. And it is all because we are looking at ourselves and comparing ourselves to others around us. But God knows what he wants, and he has grafted you into his vine because he wants what you. He knew what your grapes would look like, what they would taste like before he grafted you in, and we can trust that as long as we abide in him we are producing the fruit he wants, even if it looks to us inferior.