Man in this life of the World, may have anxiety, fear, tiredness, poverty, illness, troubles.
So when he is a child has to go to school, then will be teenager and will suffer from many aspects, then will be an adult he will have responsibilities, will face many difficulties, and will be weary for his
his family, his work:
He may suffer diseases, or may have the experience of
jail maybe and have many hazards and risks.
He also is restricted by many limitations; he has to wash and if he does not wash then his smell will be disgusting; he has also to eat and drink, and if not he will suffer starvation .
While in the afterlife, and in case he devotes himself to God alone, and admit the prophethood of all the prophets including Mohammed, and admit the revealed heavenly books: the Torah, the Gospel and the Quran
And in addition he works the righteous work for God's sake not for anyone else--> then
he will prosper in the afterlife and live a perpetual life for ever in happiness, no fear for him, no danger, no sadness, and he will have all the pleasures given to him by God Most Gracious.
Therefore, any wise man should work primarily for his afterlife in the first place.
http://quran-ayat.com/man/1.htm#The_..._more_Enduring