The Talmud states: “Our forefather Jacob never died. From where do we know this? From the verse: ‘Fear not, Jacob… for I will save you from afar and your seed from their captivity’ — just as his seed is alive, he too, is alive.” But why only Jacob? Don’t Abraham and Isaac live forever as well?

Abraham bore Ishmael, and Isaac bore Esau. Since a child’s body is formed from his parents, a part of Abraham and Isaac died along with their wicked sons... Therefore, they cannot be said to live forever. Jacob's offspring, however, were all righteous, so “just as his seed is alive, he, too, is alive.”

Jacob’s life, therefore, depends on his children’s actions. If even one Jew will not be spiritually alive, then Jacob would not be fully “alive.” It would be as if he bore an Ishmael or an Esau... Torah promises that “the entire Jewish People will return to G‑d, and immediately they will be redeemed.”