Islam is to willfully submit to the Creator of all that exists, in obedience to His commands. The result of doing so is peace.
Not all terrorists are Muslims. Instead they come from varying religions or walks of life. Some are Catholic, some Protestant, some Jewish, some Hindu, some Atheist. The reason why it may seem like most of them are Muslim is due to their religion being mentioned whenever they report their terrorism in the media. If the religion of non-Muslim terrorists was mentioned, this would greatly change the perception. Similarly if the acts of terrorism committed by those of other faiths was actually referred to as terrorism, things my seem different than they do now.
The Qur'an forbids injustice and oppression in all of its forms, including terrorism. Muslim soldiers in wartime are not allowed to attack civilians or destroy property. Muslims are not allowed to kill themselves. Muslims soldiers in wartime are to treat captives in a kind manner.
The problem lies in some weak-minded people being corrupted by the false interpretations of others, who then convince them to do these horrific acts. Similar to how the African slave trade or the bloody colonization of the Americas was seemingly justified by Christians, due to a misguided interpretation.
Islam is a religion of peace in the fullest sense of the word. The Quran calls its way "
…The ways of peace…
It describes reconciliation as the best policy [Quran: 4:128], and states that God abhors any disturbance of peace [Quran: 2:205]
The root word of Islam is 'Silm', which means peace. So the spirit of Islam is the spirit of peace. The first verse of the Quran breathes the spirit of peace; it reads: "In the name of God, the Most Merciful, the Most Compassionate." This verse is repeated in the Quran no less than 114 times. It shows the great importance Islam attaches to such values as Mercy and Compassion. One of God's names, according to the Quran, is As-Salaam, which means Peace. Moreover, the Quran states that the Prophet Muhammad (may Allah exalt his mention) was sent to the world as a mercy to mankind. [Quran: 21:107]
A perusal of the Quran shows that most verses of the Quran (and also the Hadeeth) are based on peace and kindness, either directly or indirectly. The ideal society, according to the Quran is Dar As-Salaam, that is, the house of peace [Quran: 10:25] The Quran presents the universe as a model, which is characterised by harmony and peace [Quran: 36:40] When God created heaven and earth, He so ordered things that each part might perform its function peacefully without clashing with any other. The Quran tells us that "It is not allowable [i.e., possible] for the sun to reach the moon, nor does the night overtake the day, but each, in an orbit, is swimming." [Quran: 36:40] For billions of years, therefore, the entire universe has been fulfilling its function in total harmony with His divine plan. According to Islam, peace is not simply an absence of war.
Peace opens doors to all kinds of opportunities which are present in any given situation. It is only in a peaceful situation that planned activities are possible. It is for this reason that the Quran says:
"…And settlement is best…"
Similarly, Prophet Muhammad has observed: "God grants to gentleness (Rifq) what He does not grant to violence ('Unf). [Abu Daawood] According to Islam, peace is the rule and war is only an exception. Even in defensive war we have to analyse its result; if the result is doubtful, Muslims should avoid war. Stray acts of aggression are not enough for Muslims to rush into war. They have to assess the whole situation and adopt a policy of avoidance when war is not certain to achieve a positive result. In actual fact, the mission of all the Prophets from Aadam (Adam) to 'Eesaa (Jesus), may Allah exalt their mention, was one and the same - of establishing the ideology of monotheism in the world, so that man might worship the One God alone. As we know, there came a large number of Prophets in ancient times but the message of monotheism remained at the initial stage; it could not culminate in revolution.
In ancient times, the system of monarchy was entrenched throughout the world. The kings, in order to secure their political interests, adopted the course of religious persecution. These kings suppressed all religious movements that were different from the state religion. They would nip all 'apostasy' in the bud since they saw religion as a matter of affirming one's loyalty to the state. If a person adhered to a religion other than the state religion, he was regarded as a rebel. That is why in ancient times, prophetic movements could go no further than the state of Da'wah, or invitation to Islam. No sooner would a movement based on monotheism arise than the coercive political system would be activated to pull it out by its roots. The reason for the absence of any historical record of Prophets (besides the Prophet Muhammad ) in antiquity is traceable to the intense opposition of these coercive political systems. All the Prophets of ancient times, historically speaking, were like mythical beings, rather than real human beings accepted as historical figures. Prophet 'Eesaa (Jesus), may Allah exalt his mention, was the last link in the chain of these persecutions faced by the preachers of monotheism. Then God decreed the abolition of this coercive political system, even if it entailed the use of force in order that the age of religious persecution might be brought to an end forever, and replaced by the age of religious freedom.
This Divine plan was brought to completion through the Prophet Muhammad and his companions, may Allah be pleased with them all. This is the command given in the Quran: "Fight them until there be no fitnah [i.e., persecution] and [until] the religion [i.e., worship], all of it, is for Allah…" [Quran: 8:39] Therefore, Prophet Muhammad received special divine succour in the form of a powerful team consisting of one hundred thousand individuals. Equipped with this team, the Prophet waged war to end this coercive system of religious persecution, and it was in Arabia that it was first of all overthrown. Then within a very short span of time, they advanced to abolish the coercive system established by the Sassanid and Byzantine empires. In the wake of this Islamic action, the coercive system was abolished forever in the major part of the inhabited world of the time. This war waged by Prophet Muhammad and his companions was not a war as is commonly understood, but rather a divine operation, which was carried out by people who possessed a high standard of moral character. However, this operation was certainly only temporary in nature. Its goal was to put an end to the age of religious persecution and usher in the age of religious freedom. This end was fully achieved during the early period of Islam, the age of the pious Caliphs. Afterwards the time came to keep the sword in its sheath and engage in Da'wah work, that is, the call to God, which was the real and permanent goal of Islam.
It is no exaggeration to say that Islam and violence are contradictory to each other. The concept of Islamic violence is so obviously unfounded that, prima facie it stands rejected. The fact that violence is not sustainable in the present world is enough to convince one that violence, as a principle, is quite alien to the scheme of things in Islam. Islam claims to be an eternal religion and such a religion cannot afford a principle in its scheme which will not be sustainable in later periods of human history. An attempt to bracket violence with Islam amounts to casting doubts upon the very eternity of the Islamic religion. No wonder then that the Prophet Muhammad so earnestly used to entreat his Lord in his daily prayer: "O God, you are the original source of Peace; from You is all Peace, and to You returns all Peace. So, make us live with Peace; and let us enter paradise: the House of Peace. Blessed be You, our Lord, to whom belongs all Majesty and Honour!"