Behold, therefore ... - Regard, or contemplate, for purposes of your own improvement and benefit, the dealings of God. We should look on all his dispensations of judgment or of mercy, and derive lessons from all to promote our own steadfast adherence to the faith of the gospel.
The goodness - The benevolence or mercy of God toward you in admitting you to his favor. This calls for gratitude, love, confidence. It demands expressions of thanksgiving. It should be highly prized, in order that it may excite to diligence to secure its continuance.
The severity of God - That is, toward the Jews. The word “severity” now suggests sometimes the idea of harshness, or even of cruelty. (Webster.) But nothing of this kind is conveyed in the original word here. It properly denotes “cutting off,” ἀποτομίαν apotomian from ἀποτέμνω apotemnō, to cut off; and is commonly applied to the act of the gardener or vine-dresser in trimming trees or vines, and cutting off the decayed or useless branches. Here it refers to the act of God in cutting off or rejecting the Jews as useless branches; and conveys no idea of injustice, cruelty, or harshness. It was a just act, and consistent with all the perfections of God. It indicated a purpose to do what was right, though the inflictions might seem to be severe, and though they must involve them in many heavy calamities.
On them which fell, severity - On the Jews, who had been rejected because of their unbelief.
But towards thee, goodness - Toward the Gentile world, benevolence. The word “goodness” properly denotes benignity or benevolence. Here it signifies the kindness of God in bestowing these favors on the Gentiles.
If thou continue in his goodness - The word “his” is not in the original. And the word “goodness” may denote integrity, probity, uprightness, as well as favor; Romans 3:12, “There is none that doeth good.” The Septuagint often thus uses the word; Psalms 13:1, Psalms 13:3, etc. This is probably the meaning here; though it may mean “if thou dost continue in a state of favor;” that is, if your faith and good conduct shall be such as to make it proper for God to continue his kindness toward you. Christians do not merit the favor of God by their faith and good works; but their obedience is an indispensable condition on which that favor is to be continued. It is thus that the grace of God is magnified, at the same time that the highest good is done to man himself.
Otherwise thou also shalt be cut off - Compare John 15:2. The word “thou” refers here to the Gentile churches. In relation to them the favor of God was dependent on their fidelity. If they became disobedient and unbelieving, then the same principle which led him to withdraw his mercy from the Jewish people would lead also to their rejection and exclusion. And on this principle, God has acted in numberless cases. Thus, his favor was withdrawn from the seven churches of Asia Rev. 1–3, from Corinth, from Antioch, from Philippi, and even from Rome itself.