“Outwardly the Grave is stillness while inwardly it is either punishment or bliss. The intelligent man is the one who protects himself against the evil of this punishment before it is too late. Such a man knows with certainty that sooner or later his day will come, and that this moment is known only to the Almighty Creator. It might come without warning. When it comes a man leaves behind all the wealth he has amassed and moves to another world. Only there will he feel regret. But regret then will not do him any good. In that place, only good actions are of any use. They alone will be useful currency on that critical day. Only with them will he be able to purchase a magnificent mansion in the Garden with all the luxuries and blessings it contains – an everlasting mansion, not one which disappears as things do in this world.
The intelligent man is the one who acts for this world as if he were going to live forever and acts for the Next World as if he were going to die tomorrow.”
– Ibn al-Qayyim, from an abridgement of his Kitaab ar-Rooh