But the heart of Muhammad's revelation concerned teaching humanity to live as one nation. 13 Whereas Christianity was mainly concerned with salvation of the individual, Islam took salvation a step further and taught that not only does a human have a duty towards his own spiritual advancement, but that he or she has a moral duty to live together in a community following God's will. However Muhammad announced that he was to be the last Prophet of the Adamic era. After this a time will come when he who shall observe one-tenth of what is now ordered will be redeemed. 19 God sends Prophets with different laws to suit the age in which he appears and the revelations themselves are progressive in nature.
Every religion has a matrix from which it appears.
Consequently, each Prophet had to deal with the ignorance and depravity of his own people as well as laying the foundations for the spiritual enlightenment of future generations. Two examples of this type of internal progressiveness include slavery and polygamy. Slavery has existed in some form or another for most of human existence. At the time of Muhammad, slavery was rampant and the rights and conditions of the slaves themselves were almost non-existent. A contrary policy would have produced an utter collapse of the infant commonwealth.