Allah has created everything with a fixed life span. The Quran states: It is not given to any soul to die save by Gods permission, and at an appointed time. [Ali Imran 3: 145.] Indeed there is no certainty in life except death. Every soul will taste death. [Ali Imran 3:185.]
Not only is death itself inescapable, but the place and the very day and hour of death have been forever fixed: No person knows what he will earn tomorrow and no person knows in what land he will die. [Luqman 31: 34.]
When the time arrives they cannot tarry a single moment nor can they go ahead. [an-Nahl 16: 61.]
In death, we are compelled to return to God. In life, however, we can choose to draw closer to God voluntarily by living our lives according to His will. In this way, we have the opportunity to meet Allah and gain His pleasure even before we leave this world.
Those who fail to use the bounties of Allah to earn His pleasure during this life, will forever regret their mistakes for the cessation of life brings the cessation of opportunities for redemption and salvation, as the Quran warns:
When death comes to one of them, he says, My Lord, let me return, let me return to life, so that I may act righteously in whatever I have left behind"Nay, it is but a meaningless word he utters; for behind them now is the barrier of death until the day they shall be raised up. Then, when the Trumpet will be blown, no lies of kinship will remain between them that day, neither would anyone be able to take care of another. Then, they whose weight of good deeds is heavy in the balance will attain salvation. But, they whose weight is light in the balance, will have squandered their own lives. In Hell will they abide forever. [al-Muminun 23: 99-103.]