First, you should have a more meaningful title for your essay in the subject field when you open a new thread. It is a forum rule and also it helps you earn more meaningful feedbacks.
I really never understood the meaning of death or the purpose of it.
... how about "purpose of life"?
I really never understood the meaning of death or the purpose of life.All I could understand is that it comes uninvited unexpectedly and it is inevitable, for all life will come to an end one day.
Well... this is exactly what death means and this sentence gives a different meaning to what you just said in your previous sentence. This one challenges your claim that you didn't understand what death mean. I feel you need to pay attention to this.