Gal 3:16 Now to Abraham and his seed were the promises made. He saith not, And to seeds, as of many; but as of one, And to thy seed, which is Christ.
Abraham was a jewish man, but anyone that belongs to Christ has taken the seed of Abraham. So in the eyes of God it does not matter if you are a jew or a gentile, if you are reborn under the Blood of Christ you have taken the seed of Abraham promised by God.