Coexistence in Islam
The principle underlying the relationship between Muslims and non- Muslims is coexistence. Allah commands Muslims to treat other people kindly provided they do not manifestly declare malice towards them and to think well of all of people alike. A person who thoroughly explores the verses of the noble Qur`an will find that, in its entirety, it presents an integrated Qur`anic methodology concerning the treatment of non-Muslims. It is noteworthy to mention that the variation in the manner of treating non-Muslims does not stem from a methodological inconsistency; rather, it depends on the different attitudes of the people we deal with. People are different [with respect to behavior] and thus they must not be judged alike. It is considered a methodical injustice to generalize what has been made specific or to specify what has been left general in legal texts.
Just as there are individuals who accept Muslims' beliefs, there are others who differ with them. Among this latter group, there are some who merely present their opinions or beliefs and those who go as far as to attack those who differ with them. Therefore, both groups are treated differently.
Evidence from Qur`an
There are many verses in the Qur`an, whether those revealed in Mecca or Medina, that urge Muslims to be tolerant towards others and to treat them kindly. These include:
So pardon and overlook until Allah delivers His command. Indeed, Allah is over all things competent. (Al-Baqarah: 109)
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 has grasped the most trustworthy handhold with no break in it. And Allah is Hearing and Knowing. (Al-Baqarah: 256)
Allah does not forbid you from those who do not fight you because of religion and do not expel you from your homes - from being righteous toward them and acting justly toward them. Indeed, Allah loves those who act justly. (Al-Mumtahana, 8)
The above verses from Surah al-Baqarah and al-Mumtahana were revealed in Medina and all of them exhort Muslims to be kind and merciful to their fellow men.
As for the legal texts [Qur`an and Sunnah] that command Muslims to be harsh towards some people, they can be compared to the previous verses as two integrated methodologies that deal with two different types of people:
The first methodology, which is the general case, enjoins Muslims to treat all people with kindness through dialogue and respect of freedom [of faith]. This is the correct basis for inviting others to Islam; this does not abrogate a Qur`anic verse nor has it been abrogated though some jurists claim the contrary. Allah Almighty says,
And speak to people good [words] and establish prayer and give zakah. (Al-Baqarah: 83)
In another verse, Allah instructs those who call others to His way on how they should invite others according to the different types of people:
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. (An-Nahl: 12)
Allah says about the People of the Book,
And do not argue with the People of the Scripture except in a way that is best, except for those who commit injustice among them, and say, "We believe in that which has been revealed to us and revealed to you. And our God and your God is one; and we are Muslims [in submission] to Him. (Al-'Ankabut: 46)
The second methodology is concerned with those who attack Muslims, in which case it is necessary to defend oneself. Allah Almighty says,
(Fighting in) the sacred month is for [aggression committed in] the sacred month, and for [all] violations is legal retribution. So whoever has assaulted you, then assault him in the same way that he has assaulted you. And fear Allah and know that Allah is with those who fear Him. (Al-Baqarah: 194)
Unlike the policy followed by some countries, Muslims do not treat others based on whether they are with or against them. Rather, Islam teaches its followers that people are different and must therefore be treated accordingly with respect to time and type of person.