The root word of Islam in Arabic is silm, which means peace. The teachings of Islam are based, directly or indirectly, on the principle of peace.
The message of Islam to man is to build a world of peace on earth so that he may be granted a world of peace in the eternal life hereafter. In order to preserve the peace established by nature from disruption, Islam has laid down two important injunctions. One, at the individual level, stresses the exercise of patience; and the other, at the social level, forbids taking the offensive. While all Islamic objectives may be achieved in a peaceful atmosphere, there are no Islamic objectives which may be achieved in a violent atmosphere.
The Quran is undoubtedly a book of peace. It says, 'Do not go to excess in your religion' (4:171). Therefore the way of extremism, which generally culminates in war and violence, is wrong, whatever the circumstances, for it goes against the spirit of religion. In Islam, moderation, which is the opposite of extremism is a necessary virtue for a believer to follow as a way of life.
On the subject of jihad, the Quran addresses the believers thus: 'Do great jihad with the help of the Quran' (25:52). Jihad literally means to strive, to struggle, that is to exert oneself to the utmost to achieve one's goal. Therefore, 'jihad by means of the Quran' can only mean peacefully conveying the ideology of the Quran to people. 'The Quran calls the policy of reconciliation as the best policy (4:128). The Quran further states: 'Each time they kindle the fire of war, God extinguishes it.' (5:64) This verse of the Quran shows the creation plan of the Creator.
Those who accept the Quran as the Book of God will be regarded as true believers only when they follow its admonitions completely and become peace loving.
Under no circumstances, can a believer launch himself on a violent course of action. One who abandons the teachings of Islam runs the risk of not being a believer.