We know the Zohar tells us that when, when, a Tzaddik dies, he actually is more alive in this world than before!
What is life, what is death?
Life of course is love!
If you love something it gives you an energy; on the other hand death is depression, lack of love, like the darkness that follows the bright sunlight.
So what if, what you love doesn’t die, only gets stronger?
The Tzaddik loves his fellow people, particularly those who his soul inspired, commensurate with his Divine mission- his love and awe of God are boundless.
Only bodies can separate people, but love has no body.
As the soul leaves the body, it in fact has more love, not less love!
If a person’s loves are physical, then death does represent death, a darkness, for those things that he loves are no longer accessible!
But love of people, love of and awe of God! are in fact far more accessible than ever before!