1. Islam means peace (Arabic: Salaam).Islam comes from the root word 'salaam' of Arabic language, which means peace. Islam also means submitting one's will to the all mighty Allah/(God). That is why Islam is a religion of peace, which is obtained by submitting one's will to the will of the Superlative Creator, Allah/(God).
2. Allah/(God) says in the glorious holy Quran/Koran that 'No compulsion in religion'.It is forbidden to all Muslim to do anything against the teaching of the glorious holy Quran/Koran. The glorious holy Quran/Koran says in Surah Bakarah, chapter 2 verse 256: "There shall be no compulsion in [acceptance of] the religion. The right course has become clear from the wrong. So whoever disbelieves in Taghut and believes in Allah/(God) has grasped the most trustworthy handhold with no break in it. And Allah/(God) is Hearing and Knowing."
3. Spain was ruled by Muslims for 800 years.Spain was ruled by Muslims for 800 years. The Muslims in Spain never ever used any force the people to convert. Later the Christian Crusaders came to Spain and they converted Muslims to Christianity by force and wiped out the Muslims. There was not a single Muslim in Spain who could openly give the call for prayers. If want a proof then you can see the following documentary:
4. Over fourteen million Arabs are Coptic Christians.Muslims were the overlord of Arabia nations for 1400 years. British ruled for a few years, and for a few years the French governed. In all, the Muslims ruled Arabia for 1400 years. At present, there are Fourteen million Arabs who are Coptic Christians and they are Christian since generations. If the Muslims had used any force there would not have been one single Arab who would have remained a Christian.
5. More than 80% in India are non-Muslims.The Muslims governed India for about a thousand years. They had the strength of converting every and each non-Muslim of India to Islam if they wanted. Today more than 80% of the population of India are non-Muslims. Today all these non-Muslim Indians are bearing witness that Islam was not spread by the force or sword .
6. Malaysia and Indonesia.Maximum number of Muslims in the world are in Indonesia. In Malaysia the majority of people are Muslims. May one ask, "Which Muslim force went to Malaysia and Indonesia?"
7. East Coast of Africa.likewise, Islam has spread rapidly on the East Coast of Africa. How it was happened, if Islam was spread by the force or sword, "Which army of Muslims went to the East Coast of Africa?"
8. Consideration of the historian De Lacy O'Leary's opinion.The best reply to the false allegation or misconception that Islam was spread by the sword is given by the famous historian De Lacy O'Leary in the book "Islam at the cross road" (Page 8): "History makes it clear however, that the legend of fanatical Muslims sweeping through the world and forcing Islam at the point of the sword upon conquered races is one of the most fantastically absurd myth that historians have ever repeated."
9. Consideration of the historian Thomas Carlyle's opinion.The leading historian, Thomas Carlyle, in his book "Heroes and Hero worship", refers to this allegation or misconception about the expansion of Islam: "The sword indeed, but where will you get your sword? Every new opinion, at its starting is precisely in a minority of one. In one man's head alone. There it dwells as yet. One man alone of the whole world believes it, there is one man against all men. That he takes a sword and try to propagate with that, will do little for him. You must get your sword! On the whole, a thing will propagate itself as it can."
10. Consideration of Dr. Joseph Adam Pearson opinion.Dr. Joseph Adam Pearson properly says, "People who worry that nuclear weaponry will one day fall in the hands of the Arabs, fail to realize that the Islamic bomb has been dropped already, it fell the day MUHAMMED was born".
11. Sword or force of the Intellect.It is actually the force/sword of intellect. The force that conquers the minds and hearts of people. The glorious holy Quran/Koran says in Surah Nahl, chapter 16 verse 125:
"Invite to the way of your Lord with wisdom and good instruction, and argue with them in a way that is best. Indeed, your Lord is most knowing of who has strayed from His way, and He is most knowing of who is [rightly] guided." [Al-Quran 16:125]