“For if the firstfruit be holy, the lump is also holy: and if the root be holy, so are the branches. And if some of the branches be broken off, and thou, being a wild olive tree, wert graffed in among them, and with them partakest of the root and fatness of the olive tree; boast not against the branches. But if thou boast, thou bearest not the root, but the root thee.” (Romans 11:16-18)
As the climax to all that has been discussed up to this point concerning salvation, Paul gives the illustration of grafting. To prevent misunderstanding and improper exegesis, some detailed explanation is necessary concerning the three groups which are presented in the coming passages. For the remainder of the chapter, Paul is not addressing the Church specifically. He is addressing Gentiles. The root of this olive tree cannot be thought of solely as salvation, because this will lead to doctrinal contradiction. In context, the root represents the patriarchal faith of Abraham, Isaac, and Jacob. In the simplest terms, it consists of Christ and faith in His Person. The olive tree is one of the longest living trees in the world. A lifespan of 1,500 to 2,000 years is not uncommon. In comparison to other trees, it may be thought of as “living forever;” therefore, it is quite befitting that such a tree should be used to illustrate matters which deal with eternal life. The unfruitful branches which have been cut off, represent unbelieving Israel as a nation. The fruitful branches represent the general assembly of the Gentiles. Having identified the three groups represented by the illustration, a discussion on the purpose and particulars of grafting is in order.
Grafting is an ancient art which allows the best of both worlds to be incorporated into one hardy, fruitful olive tree. A root system which is well founded and already thriving in its current environment is first selected. It is then pruned of all its unfruitful branches until just the main body of the tree remains (this process of pruning may be less or more dramatic depending upon the needs of the farmer). Fruit-bearing branches from a good tree are then attached to the ends of the limb bases. Over a period of some weeks, the branches and the body of the tree will fuse themselves together. The result is a tree with a well established root system and fruitful branches. The branches do not take on the identity of the natural branches which were pruned, but they are nourished by the root, thus allowing for fruit to be produced.
With this horticultural illustration in mind, God presents a picture of what He has accomplished through the ministry of Jesus Christ. The covenant of faith which was established with Abraham cannot be broken. It is firmly founded in the “root system” of this illustration. The nation of Israel had the opportunity to be nourished by this covenant; however, they rejected their Messiah; therefore, as a nation, they were removed from the olive tree, thus indicating that God has ceased to reach out to them in a special way, but only for the time being. Knowing that the Gentile nations would respond to faith in Christ, God turned His attention to these “wild branches” and is currently giving them a special opportunity to be nourished by the root of faith. These wild branches have not become, nor have they replaced, the natural branches. They have simply been given opportunity to partake of the root's life-giving qualities. The branches do not sustain the root. The root sustains the branches.