The word ‘Islam’, which is derived from ‘aslama’, means surrender to the Will of God. The word has other meanings  too – to be at perfect peace, to have done one’s duty to the Master, to strive after righteousness, and to greet safety and salvation. It believes that in obedience of God, lies peace, prosperity, happiness, and the salvation of man. According to Islam, the other prophets who preceded Muhammad were all true prophets, and Islam is nothing but a confirmation of the true faith taught by previous religions and teachers. Religion is certainly a vital force in every society and Muhammad made Islam a permanent force of vitality by giving it a natural and rational basis. He emphasised the universal concept of religion such as the unity of God and the unity of the human race. The essence of tawhid or the unity of God as a working idea is equality, solidarity, brotherhood and freedom. It is a change from heterogeneity to homogeneity, from diversity to unity and from confusion to order.
Dimensions of Islamic effects
Islam’s concept of the unity of man had very deep and far-reaching effects on the social, political, economic and moral way of life of the Muslims. It is eminently human because it takes man for what he is. The prophet was sent not to make life more difficult, but to facilitate it. The requirements of Islam are easy and simple. The striking feature of Islamic teaching, which is so well brought out is the equality and brotherhood of man. It attempts to level the barriers of caste, colour and class and takes its stand on the bedrock of love, liberalism and brotherhood. The Quran says, ‘ Oh people! be fearful of God who has created you all from the same single soul’. This unity of man was of great social value. It removed all discriminations in human society and had established the value of merit, ability and the capacity to wield the sword that mattered most, and not the race, colour or the social distinction. In the Muslim period of Indian history, slave after slave succeeded to political power and established a Slave Dynasty itself, holding power for nearly a century. 
An  impression  has  been  created  that  Islam  is  intolerant of other religions. The Quran emphatically declared, ‘There is no compulsion in religion’, and again ‘Unbelievers who worship other things than God need not be blamed lest they should abuse God in their ignorance.  It is true that jehad or holy war is permitted in Islam, but Jehad is a fight against those who fight against you.  It is a defensive war sanctioned by the prophet at an extraordinary period when the Kuraish were bent upon wiping out the Muslims.  It does not permit the Muslims to commit aggression.  Later theologians have interpreted jehad as a struggle to create something new and change the order through intellectual power, and it is not necessarily the use of physical force.
Concept of intolerance is relative
Unfortunately, this intolerance is the common heritage of all the three semitic religions –Judaism, Islam and Christianity.  The misfortune of Islam is that it has no Reformation, no Renaissance.  This situation, said Sri Aurobindo, needs to be corrected.  “We must strive to remove the causes of misunderstanding by mutual knowledge and sympathy and spread the just views of Mohammedan history and civilisation.  What is wanted is some new religious movement among the Mohammedans which would remodel their religion and change the stamp of their temperament. Although Islam has had no reformers because of the belief in the immutability of the doctrine.  The same conviction guides the Christian Right, mainly in the US.  They oppose Darwin’s theory since it negates the Word of God in the Bible. Lots of people all over the world have the feeling that Islam is intolerant and violent.  And this is true enough.  The concept of Kafir and Jehad are wholly unacceptable, especially in its present form and interpretation.
Islam started as a great revolutionary movement based on equality, human dignity and justice. These ideals were partly acceptable to the tribal society of Mecca.  Equality and human dignity was acceptable in a limited way within tribal social boundaries.  Members of a tribe could be accepted as equals, but not those of  other tribes.  Members of other tribes could be accepted only as a client, not as an equal.  Hence, the concept of universal brotherhood and inter-tribal equality created social tension throughout the Islamic history. Within Arab society, these became explosive after the death of the prophet.  By the time the prophet died, different tribes of Arabia had embraced Islam.  Sociologically speaking, ‘hostile’ tribes also entered the fold of  Islam leading to tension between them. The lofty ideals received a setback when the tribe of Quraysh claimed the Caliphate quoting a ‘hadith’ and superiority over other tribes.  These concepts were never accepted sociologically.  Islamic society soon transformed into a feudal society.  The reasons for embracing a religion could be quite varied.  Some embrace it collectively along with other members of the caste or tribe or nation; some embrace it for political or economic advantages ; and some after studying the religion.  Normally the social structure does not change, but religious practices do.  Arab society has remained tribal in structure till this day.  Had Islamic ideals and values prevailed, Arab society would have undergone radical changes and tribal norms and values would have been replaced by Islamic ones. Thus, it would be very difficult to talk of a ‘pure’ Islamic culture.  Each Muslim society has its own distinct tribal or national or ethnic culture even though ritual practices may be the same.
Significance and justification of religion
The continued presence of religion in the public sphere is justified on two grounds.  First it is argued that religion per se is not responsible for the kind of hostility and hatred that we witness among members of different communities today.  Second, and more importantly, it is argued that ‘communal violence’ is a contemporary phenomenon embodying a system of rationality that is characteristic of modernity.  Industrial development displaces large sections of the population from their original surroundings, resulting in a deep sense of dislocation and alienation.  At the same time it fails to provide an alternative set of values and along with it, a sense of belonging to these people.  To offset this deficiency they try to reclaim and assert their traditional identities more stridently.  The alienation generated in the process of modernisation provides the material for the growth of orthodox religious forms.
In more positive term, the principles of modernity claim that the theme of tolerance, which defines a liberal democratic framework, is an attribute of all lived and practised religion. Continuous interaction with members of other communities in the course of everyday life, generates a degree of tolerance and diversity in which religious boundaries become fuzzy as members of one community participate in the religious and cultural practices of the other.  In contemporary India, despite the increasing incidents of communal violence, we find Hindus visiting ‘gurudwaras’ and rubbing shoulders with the Muslim pilgrims at the Chishti Dargah in Ajmer.