Against Heresies: Book V

THIS TRUTH: therefore, he declares, so we do not reject the engrafting of the Spirit while indulging the flesh. "But you, being a wild olive tree," he says, "have been grafted into the good olive tree, and made a partaker of the fatness of the olive tree." Just as when the wild olive is grafted, if it remains in its original state, that is, a wild olive, it is "cut off and cast into the fire"; but if it adapts to the graft and transforms into the good olive tree, it becomes a fruit-bearing olive, planted, as if in a king’s park (paradise): likewise, men, if they truly progress by faith toward better things, receive the Spirit of God, and bring forth its fruit, shall be spiritual, as being planted in the paradise of God.

But if they cast out the Spirit and remain in their original state, preferring the flesh over the Spirit, then it is right to say of people like this, "Flesh and blood shall not inherit the kingdom of God," just as one might say the wild olive is not welcomed into the paradise of God. The apostle admirably illustrates our nature and God’s universal plan in his discussion about flesh and blood and the wild olive. For just as the good olive, if neglected for a time, becomes wild and woody, it turns into a wild olive; or if the wild olive is carefully tended and grafted, it naturally returns to its former fruit-bearing condition: so men also, when they become careless and produce as their fruit the desires of the flesh like woody growth, are made, by their own fault, unfruitful in righteousness.

For when men sleep, the enemy sows the seeds of tares; and for this reason, the Lord commanded His disciples to be watchful. And again, those who are not bringing forth the fruits of righteousness and are, as it were, overgrown and lost among brambles, if they are diligent and receive the word of God as a graft, return to the original nature of man—that which was created after the image and likeness of God.

Just as the grafted wild olive doesn't lose its wood but changes the quality of its fruit and gets a new name, becoming a fruit-bearing olive, so too does a person, when grafted by faith and receiving the Spirit of God, not lose their physical nature but change the quality of their deeds. They receive a new name, showing they have improved, becoming a spiritual individual. If the wild olive is not grafted, it remains useless to its owner and is cut down and burned, because it doesn't bear fruit.

SIMILARLY: if a person does not receive the Spirit through faith, they remain in their old state and, being mere flesh and blood, cannot inherit the kingdom of God.

Thus, the apostle rightly states, “Flesh and blood cannot inherit the kingdom of God,” and, “Those who are in the flesh cannot please God.” These words don't reject the body but show that the Spirit must be infused into it. For this reason, he says, “This mortal must put on immortality, and this corruptible must put on incorruption.” He further clarifies, “But you are not in the flesh, but in the Spirit, if indeed the Spirit of God dwells in you.” He explains further, “The body is dead because of sin; but the Spirit is life because of righteousness.

But if the Spirit of Him who raised Jesus from the dead dwells in you, He who raised Christ from the dead will also give life to your mortal bodies through His Spirit dwelling in you.” And again in the Epistle to the Romans, he says, “For if you live after the flesh, you shall die.” He doesn't forbid them from living in the flesh—he was in the flesh himself when he wrote this—but he warns against the desires of the flesh, which bring death.

Therefore, he continues, “But if you, through the Spirit, put to death the deeds of the body, you shall live. For those who are led by the Spirit of God are the children of God.”