From the Saviours own lips we have proof that the Jews are not of any of the tribes of Israel.
Note carefully that He does not say that their unbelief keeps them from being His sheep. He says the exact opposite. That the reason that they do not believe is because they are not His sheep.
Jesus speaking to the Jews, John [10]
But, ye, believe not, because ye are not of my sheep. My sheep, unto my voice, hearken,––and, I, know, them, and they follow me,
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