If you die before you die then

You won’t die when you die

If you die —  if your ego-self dies

Before you die — prior to the death of your physical body,

Then you won’t die — then your essence-self will not die

When you die.  — when your physical body dies.

Briefly put, then: we must let go of our ego-self so that our essence-Self will emerge and remain.  If our ego-self dies, our essence-Self will never die.