This isn’t original. I think Patrick Madrid said something like it:
Think of Life as wet cement, able to be formed, impressed, changed. Death is comparable to the hardening of the cement. Now, it’s final shape is set, and can’t be changed. Life is for choices, death is finality and conclusion. Life is a time not only of choice but of Mercy.
The situation is that with Death, we are set for Eternity. This side of eternity is important, for once eternity is upon us, we can’t take our choices back. God respects our free will choice, even when we choose to exist without Him. Existence without God is Hell.