Certainly, fear of Allah is the key to guidance, provision for the next world, freedom from every slavery and deliverance from all ruin. With its help the seeker succeeds and he who makes for safety escapes and achieves his aims.
Perform (good) acts while such acts are being raised (up to Allah), while repentance can be of benefit, prayer can be heard, conditions are peaceful and the pens (of the two angels) are in motion (to record the actions). Hasten towards (virtuous) actions before the change of age (to oldness), lingering illness or snatching death (overtakes you). 
Certainly, death will end your enjoyments, mar your pleasures and remove your objectives. It is an unwanted visitor, an invincible adversary and an unaccounting killer. Its ropes have entrapped you, its evils have surrounded you, its arrowheads have aimed at you, its sway over you is great, its oppression on you is continuous and the chance of its missing you is remote.
Very soon you will be overwhelmed with the gloom of its shades, the severity of its illness, the darkness of its distresses, the nonsense utterances of its pangs, the grief of its destruction, the darkness of its encompassment and the unwholesomeness of its taste. It will seem as if it has come to you all of a sudden, silenced those who were whispering to you, separated your group, destroyed your doings, devastated your houses and altered your successors to distribute your estate among the chief relatives, who did not give you any benefit, or the grieved near ones who could not protect (you), or those rejoicers who did not lament (you).
Therefore, it is upon you to strive, make effort, equip yourself, get ready and provide yourself from the place of provision. And let not the life of this world deceive you as it deceived those before you among the past people and by-gone periods -- those who extracted its milk, benefited from its neglectfulness, passed a long time and turned its new things into old (by living long). Their abodes turned into graves and their wealth into inheritable estate. 
They do not know who came to them (at their graves); do not pay heed to those who weep over them, and do not respond to those who call them. Therefore, beware of this world as it is treacherous, deceitful and cheating, it gives and takes back, covers with clothes and uncovers. Its pleasure does not last, its hardship does not end and its calamity does not stop.
They are from among the people of this world but are not its people, because they remain in it as though they do not belong to it. They act herein on what they observe and hasten here in (to avoid) what they fear. Their bodies move among the people of the next world. They see that the people of this world attach importance to the death of their bodies but they themselves attach more importance to the death of the hearts of those who are living.
(1) Ibn al-'Athir, al-Nihayah, I, 355, II, 61, 103, III, 174;
(2) al-'Amidi, Ghurar, 112, 148, 213.