Always, we should be cautious in appealing to Religion (Judaism), Ethnicity (Being Jew) or Morality (having the Law). It is by faith alone. Consider the following. In Luke 3:8, John the Baptist states:
8 Therefore bear fruits in keeping with repentance, and do not begin to say to yourselves, ‘We have Abraham for our father,’ for I say to you that from these stones God is able to raise up children to Abraham.
Compare that with Paul in Romans 9:6-8.
6 But it is not as though the word of God has failed. For they are not all Israel who are descended from Israel; 7 nor are they all children because they are Abraham’s descendants, but: “THROUGH ISAAC YOUR DESCENDANTS WILL BE NAMED.” 8 That is, it is not the children of the flesh who are children of God, but the children of the promise are regarded as descendants.