One of the wise people once said: "I am amazed at the one who feels grief over the loss of his wealth but yet he does not feel grief over the loss of his life span (which occurs daily)."
So strive hard in worship (of Allah), weep over your sins and flee from the punishment (in the Hereafter). The victorious one is he who directs his hopes toward that which is everlasting and cuts off his aspirations for that which is temporary.
When Muhammad bin Sirin was about to die, he wept. It was said to him: "Why are you weeping?" He replied: "I am weeping due to my lapses in the days that have passed and the small number of deeds that I performed seeking the lofty Paradise."