For in truth you now stand in a single moment that lies between two other moments, and that moment is your entire life: it is the present, poised between what has passed and what is yet to come.
What has passed you can set right through repentance, remorse, and seeking forgiveness. That involves no toil, hardship, or strenuous bodily exertion; it is an act of the heart alone.
As for what is to come, you can guard it by refraining from sin. Such refraining is mere abandonment and relief; it is not a physical task that weighs on you, but a firm, unshakeable resolve that brings rest to your body, your heart, and your innermost being.
Thus the past is repaired by repentance, and the future is secured by abstention, determination, and intention. In neither case do the limbs bear any fatigue. The decisive matter, however, is your lifespan—this present instant between the two times. If you waste it, you waste your happiness and salvation; but if you preserve it while rectifying the moments before and after it as described, you will be saved and will gain rest, delight, and bliss. Guarding this present is harder than correcting what is before and after it, for guarding it means obliging your soul to occupy itself with what is most fitting for it, most beneficial to it, and most effective in securing its felicity—and in this regard people differ from one another more than in anything else.
Indeed—by Allah—these present days of yours are the span in which you gather provisions for your ultimate return, either to Paradise or to Hell. If you make of them a path to your Lord, you will attain the greatest happiness and the supreme triumph in this brief period that bears no comparison to eternity. But if you prefer passions, comforts, amusement, and play, the days will flee swiftly and will leave you with an immense, everlasting pain whose endurance is far more taxing, more difficult, and more enduring than the effort required to be patient in abstaining from Allah’s prohibitions, in persevering in His obedience, and in curbing the whims of the self for His sake.