Because it is clear that God gave the Promise land to the Jews.
Isn't Jesus the seed who receives the promise?
Galatians 3:15-29
15 Brothers (I speak according to man), if a man"s testament has been confirmed, no one would reject it or add to it.
16 The promises were made to Abraham and to his offspring. He did not say, "and to descendents," as if to many, but instead, as if to one, he said, "and to your offspring," who is Christ.
17 But I say this: the testament confirmed by God, which, after four hundred and thirty years became the Law, does not nullify, so as to make the promise empty.
18 For if the inheritance is of the law, then it is no longer of the promise. But God bestowed it to Abraham through the promise.
19 Why, then, was there a law? It was established because of transgressions, until the offspring would arrive, to whom he made the promise, ordained by Angels through the hand of a mediator.
20 Now a mediator is not of one, yet God is one.
21 So then, was the law contrary to the promises of God? Let it not be so! For if a law had been given, which was able to give life, truly justice would be of the law.
22 But Scripture has enclosed everything under sin, so that the promise, by the faith of Jesus Christ, might be given to those who believe.
23 But before the faith arrived, we were preserved by being enclosed under the law, unto that faith which was to be revealed.
24 And so the law was our guardian in Christ, in order that we might be justified by faith.
25 But now that faith has arrived, we are no longer under a guardian.
26 For you are all sons of God, through the faith which is in Christ Jesus.
27 For as many of you as have been baptized in Christ have become clothed with Christ.
28 There is neither Jew nor Greek; there is neither servant nor free; there is neither male nor female. For you are all one in Christ Jesus.
29 And if you are Christ"s, then are you the offspring of Abraham, heirs according to the promise.
