"I have been ordered by God to fight with people till they bear testimony to the fact that there is no God but Allah and that Mohammed is his messenger, and that they establish prayer and pay Zakat (money). If they do it, their blood and their property are safe from me" (see Bukhari Vol. I, p. 13)
story of Abu Sufyan:When Muhammad and his followers were about to attack Mecca to subjugate it to Islam, his adherents arrested Abu Sufyan, one of Mecca’s inhabitants. They brought him to Muhammad. Muhammad told him: "Woe to you, O Abu Sufyan. Is it not time for you to realize that there is no God but the only God?"
Abu Sufyan answered: "I do believe that."
Muhammad then said to him: "Woe to you, O Abu Sufyan. Is it not time for you to know that I am the apostle of God?"
Abu Sufyan answered: "By God, O Muhammad, of this there is doubt in my soul."
The ’Abbas who was present with Muhammad told Abu Sufyan: "Woe to you! Accept Islam and testify that Muhammad is the apostle of God before your neck is cut off by the sword."
Thus he professed the faith of Islam and became a Muslim.
Surah 9:5
But when the forbidden months are past, then fight and slay the pagans wherever you find them, and seize them, beleaguer them, and lie in wait for them in every strategem (of war); but if they repent, and establish regular prayers and practice regular charity, then open the way for them: for Allah is Oft-forgiving, Most Merciful.
Yusaf Ali, Abdullah.
The Qur'an Translation. Seventeenth US ed. Elmhurst, New York: Tahrike Tarsile Qur'an, Inc., 2006. 114.