Islam religion belief and law was revealed to the prophet [peace be upon him] from Allah and it is the seal of religions and the prophet is the seal of the prophets.Before Islam ,the people on earth were in aberration and paganism .Magi(Zoroastrainism)is in the east and Christendom is in the west and most of Arab countries and Jewish is in the most of Arabian penensulla .These kinds of religions affected on people’s life and spread corruption and paganism around the world.Also,with these religions the message of Allah was disappeared so,people in this sensitive time and situation need one prophet and message to take them from darkness to light again and this will be a mercy from Allah to rescue them.Also, the prophet’s mission was the last one which carries the great religion (Islam) among the world.This is Islam with its completed aspects as Allah said in the holy Qura’n {This day, I have perfected your religion for you, completed My Favour upon you, and have chosen for you Islâm as your religion.} Sûrat Al-Mâ’idah 3.
It is the Lord’s justice to make this religion fair among slaves and this is the greatest happiness which everyone look for.We can see through the holy Qura’n and sunnah how did Islam give everyone his rights and prevented injustice and aggression.Anyone can
See the justice of Islam in the society of Muslims through dealing ,manners and in the other aspects of life no preference for one on one , black or white small or big all are equal in the balance of Islam as Allah said in the holy Qura’n{O mankind! We have created you from a male and a female, and made you into nations and tribes, that you may know one another. Verily, the most honourable of you with Allâh is that (believer) who has At-Taqwâ [i.e. he is one of the Muttaqûn (the pious. See V.2:2)]. Verily, Allâh is All-Knowing, All-Aware. 47/12. By this vers we all know that the balance is not rich or lineage or position but piety and fearing Allah and following his book and his messenger
Muhammad (pbuh).This is the top of happiness.