Those words that are in bold are the extracted words pertaining to the history of Prophet Muhammad from Wikipedia, the free encyclopedia:

Muhammad ibn 'Abdullah (also spelled Mohammed or Muhammed) (ca. 570 Mecca - June 8, 632 Medina), is the foundation of the religion of Islam and is regarded as Muslims as a mesenger and prophet of God (Arabic: Allah), the last and the greatest law-bearer in a series of prophets. Muslims consider him the restorer of the uncorrupted original monotheistic faith (Islam) of Adam, Noah, Abraham, Moses, Jesus and other prophets. He was also active as a diploma, merchant, philosopher, orator, legislator, reformer, military, general, and, according to Muslim belief, an agent of divine action.

It is mentioned above that Prophet Muhammad is regarded to be the messenger and prophet of God, the last and the greatest law-bearer in a series of prophet. As he is the last law-bearer in a series of prophet, it is rational for moderate Muslims to accept that the Holy Quran to be the only source that is reliable for meditation and it is not justifiable for anyone to use the words from other muslims, especially the words from muslim extremists, in replacement of the words from Allah.

Born in 570 CE in the Arabian city of Mecca, he was orphaned at a young age and brought up under the care of his uncle Abu Talib. He later worked mostly as a merchant, as well as shepherd, and was first married by age 25. Discontented with life in Mecca, he retreated to a cave in the surrounding mountains for meditation and reflection. According to Islamic beliefs it was here, at age 40, in the month of Ramadan, where he received his first revelation from God.

According to Muslim tradition, Muhammad's wife Khadija was the first to believe he was a prophet. She was soon followed by Muhammad's ten-year-old cousin ali ibn Abi Talib, close fiend Abu Bakr, and adopted son Zaid.

From the above statements, it is obvious that Prophet Muhammad actively involved in preaching the message of Allah and that caused his wife to be the first to become Muslim. After the conversion to Muslim by his wife, his friend, his close friend and adopted son, were lately to be converted to Muslims as well. At that time when Prophet Muhammad received the revelation from Allah, he did not slaughter his wife, friend and adopted son since they were not Muslims at all in the beginning. Prophet Muhammad was willing to spare his time to reach out to the pagans and that lead to the conversions to muslims one to be followed by another. For instance, if Prophet Muhammad was a selfish and cruel man, he would simply hide the message of Allah from his close firiend and his adopted son without showing mercy to reach out to them so as to patiently wait for their repentance to become muslims since they were not muslims initially at all.

Three years after this event Muhammad started preaching these revelations publicly, proclaiming that 'God is One', that complete 'surrender' to him (lit islam) is the only way (din) acceptable to God, and that he himself was a prophet and messenger of God, in the same vein as other Islamic prophets.

The statement as mentioned above tells us that Prophet Muhammad actively involved in preaching the message of God publicly three years after receiving the revelation from Allah. If Prophet Muhammad was cruel and that Allah's mission for him was to slaughter non-muslims as long as they'd found them, Prophet Muhammad would not spend time to preach to the public since he would began his battle to slaughter all the surrounding pagans. As Prophet Muhammad did not slaughter the pagans immediately after receiving revelation from Allah and yet he began to preach to be public actively, it implies that he is a righteous man that he would not like to see pagans to suffer in the Last Judgment Day and that caused him to begin his mission to preach the message of Allah to be public. Thus, he was indeed merciful to the pagans and he did not want to see pagans to perish during the Last Judgment Day.

Muhammad gained few followers early on, and was met with hostility from some Meccan tribes; he and his followers were treated harshly. To escape persecution Muhammad and his followers migrated to Medina (then known as Yathrib) in the year 622 CE. This event, the Hijra, marks the beginning of the Islamic calendar. In Medina, Muhammad united the conflicting tribes, and after eight years of fighting with the Meccan tribes, his folloers, who by then had grown to ten thousand, conquered Mecca. In 632, a few months after returning to Medina from his Farewell pilgrimage, Muhammad fell ill and died. By the time of his death, most of the Arabian Peninsula had converted to Islam; and he united the tribes of Arabia into a single Muslim religious polity.

it is mentioned above that Meccan tribes were hostile to Muhammad. As he and his followed were treated harshly by the Mecann tribes and that caused him to trigger off the war against them. From the statement above, it is prudent to support that Prophet Muhammad did not fight initially after receiving the revelation from Allah. Instead, he actively involved in preaching the message of Allah to the pagans. He only fought back when the pagans began to trigger off their battle with him. However, muslim extremists do not like to preach the message of Allah to non-muslims and they want to slaughter them one by one without leaving any mercy and hope for their repentance.

The revelations (or Ayat, lit. 'Signs of God') - which Muhammad reported receiving until his death - form the verses of the Qur'an, regarded by Muslims as the 'Word of God' and around which the religion is based. Besides the Qur'an, Muhammad's life (sira) and traditions (sunnah) are also upheld by Muslims. They discuss Muhammad and other prophets of Islam with reverence, adding the phrase peace be upon him whenever their names are mentioned. While conceptions of Muhammad in medieval Christendom and premodern times were largely negative, appraisals in modern times hve been far less so. Besides this, his life and deeds have been debated by followers and opponents over the centuries.

source: www.danielpipes.org