It is promised that we all are to die once, either by accident, illness or eventual old age, though a few commit suicide. There is no exception to this promise.
This marching on toward "reaching full maturity" is not "full" until that "maturity" fulfilment reaches a timely death as it inextricably must conclude. Will you understand the truth of these words? No test will resolve you of this mandate. Living eternally in this vale of tears would be no gift, but rather a torment similar to hell.