"if thou continue in his goodness; meaning not the love, grace, and free favour of God, or the grace of the Spirit, a continuance in which no "if" is to be put upon; for such who are interested in the love of God always continue in it, and nothing can separate them from it; and such as have the graces of the Spirit implanted in them, as faith, hope, and love, can never lose them; these always remain in them, and they in the possession of them, though not always in the exercise of them; but the goodness of God in a church state is here meant, as the means of grace and comfort, the ministration of the word and ordinances; and the sense is, if thou dost not despise the riches of divine goodness in a church relation, if thou dost not abuse it, or walk unworthy of it, if thou abidest by it, and retainest a value for it, thou wilt still share the advantages of it:
otherwise thou also shall be cut off; from the good olive tree, the Gospel church state, into which the Gentiles were taken; and which, with respect to particular persons, may intend the act of excommunication by the church, expressed in Scripture by purging the old leaven, putting away the wicked person, withdrawing from such that are disorderly, and rejecting heretics, that is, from the communion of the church; and with respect to whole bodies and societies, an entire unchurching of them by removing the Gospel, and the ordinances of it; which threatening has been awfully fulfilled in many Gentile churches, in Asia, Africa, and Europe; and therefore may serve to awaken our fear, care, and caution, lest we should be treated in like manner."
- excerpt from John Gill's Bible commentary on Romans 11:22