Any kind of positive effort and work to earn a livelihood is undoubtedly a kind of worship and servitude to Allah the Almighty. In many verses of the Qur'an, Allah has ordered His slaves to enliven the earth and to find permissible livelihoods by practicing trade and every means of permissible dealing. He has ordered them to obey and worship Him, and in return, there will be rewards on the Day of Resurrection. Tasks like trading, muzara’a (agricultural partnership), musharaka (participation financing), mudaraba, industry; teaching others different crafts, such as sewing, dyeing, tanning, breeding chickens and cattle; many other activities if they are practiced according to Islamic and humane principles will be positive ways to get material blessings. If we try to get our livelihoods through these legal means, we will gain the love and contentment of Allah. However, if we get our livelihoods through illegal means, which are contrary to the Islamic principles and human values, we will be liable to the wrath of Allah.
The Holy Qur'an confirms this:
“O you who believe! Do not devour your property among yourselves falsely, except that it be trading by your mutual consent. 4:29”
“O men! Eat the lawful and good things out of what is in the earth, and do not follow the footsteps of the Satan; surely he is your open enemy. 2:168”
What is legal, permissible in the Islamic Sharia and utilized without waste is permissible. Things like food and drink, even if they are permissible, if obtained illegally, are forbidden, too. In any case, these things must be given back to their real owners.
 A commercial association whereby an investor entrusts capital to an agent who trades with it and shares with the investor a pre-determined proportion of the profits.
source : REPENTANCE THE CRADLE OF MERCY By Husayn Ansariyan