Romans 11:22-23 — Behold therefore the goodness and severity of God: on them which fell, severity; but toward thee, goodness, if thou continue in His goodness: otherwise thou also shalt be cut off.
And they also, if they abide not still in unbelief, shall be grafted in: for God is able to graft them in again.
severity — the present, temporary dealing of God with unbelieving Israel
cut off — The warning here does not signify that a believer can lose his salvation. Paul is not now dealing with the subject of individual union with Christ. That he had shown in chapter 8 to be inseperable (8:1 and 30-39). He is here speaking of the principles upon which God has acted towards Jew and Gentile. The Gentile needs to be warned of the danger of an evil heart of unbelief as much as a Jew, and of coming under the disciplinary severity of God. — W.E. Vine, The Epistle to the Romans, page 168.
grafted in — rejection of Israel, not irrevocable