For those whose being is the body, the death of the body is the death of the self. But for those whose being is love, awe, and faith, there is no death, simply a passage. From the state of confinement to the body, one makes a passage to liberation. One continues to work in this world, even more so than before.
The Talmud says that Jacob, our patriarch, never died. Moses, too, never died. Nor did Rabbi Yehuda HaNasi. They were very exalted souls who were one with the Truth, and since the Truth never dies, neither did they.
Yes, in our eyes there is death. A body is buried, and we must mourn the loss. But this is only part of the falsehood of our world. In the World of Truth, they are still here, just as before.
And the proof: We are still here.