In these passages, Paul tells the new Gentile believers not to be arrogant in their newfound belief in Jesus, that they were favored over the Jews. Paul tells the Gentiles that God allowed them to be ‘grafted into the olive tree,’ just as some of the branches representing the Jews were broken off.
The Jews were ‘broken off’ for their unbelief; and the Gentiles were grafted in because of their belief. Paul said, “Behold the kindness and severity of God; to those who fall, severity, but to you, God’s kindness, if you continue in his kindness; otherwise you also will be cut off.”
This passage is contrary to the doctrine of ‘assurance of salvation’ taught by many churches today. Paul’s words indicate that our favor with God is conditional on our continued belief, as evidenced by our obedience to God. As humans we always have the choice to believe or not believe. Unfortunately, we have the ability to turn away from God to evil and sinful pursuits.
The Bible says that we will be judged on our state of belief when we die. The good we might have done earlier will not be remembered if we turn away from it and forsake God. The Bible says that we must ‘endure to the end to be saved.’