Romans 10:21

From Isaiah 65:2. Gainsaying] i.e. contradicting.

It was obvious that the Church of Christ was coming to be almost entirely a Gentile Church, and that the Jews as a whole were refusing to accept Jesus as their Messiah. The Jew argued from this fact that Christianity could not be true. For if the Christian Church were really the fulfilment of the promised Messianic kingdom, and if the Jews were shut out from it, then God's promises to the Jews in the OT. would have been broken, which could not be imagined.
In Romans 9-11, St. Paul grapples with this objection:—
(1) He points out that in previous epochs God had narrowed His choice, making a fresh selection out of those already selected; and He may be acting so again (Romans 9:1).

(2) God is supreme. He may choose His instruments as He will, and we have no right to criticise (Romans 9:14).

(3) If the Jews have failed, it is because of their unbelief (Romans 10).

(4) After all, there may be more faithful Jews than is supposed, as in the time of Elijah (Romans 11:1).

(5) Seeing the reception of the Gentiles, the Jews themselves may be stirred up to accept Christ. God has forgotten neither them nor His promises, and His gracious purpose will not fail (Romans 11:11).

It should be noted that these Chapter s mainly treat of the selection by God of nations and Churches to spiritual functions and responsibilities. They have nothing to do with the predestination of individuals to salvation or condemnation, and the argument closes with the statement that what God has done has been with the purpose of having mercy upon all (Romans 11:32). While these Chapter s assume that God chooses His instruments for reasons which we cannot fathom, and which are independent of human merit and of birth or nationality, at the same time there are conditions which must be fulfilled on man's part. Those who have been chosen or elected, are free to fall away; they have done so in the case of the Jewish nation—they may do so in the case of the Gentile Church. They can only retain their position by 'faith,' i.e. here, by submitting themselves to God's purpose (Romans 10:20.).