It is a law of nature that differences will always exist among people. Everywhere and at all times there have been diverse colours, tongues, customs, concepts, intellects and degrees of knowledge. All that is a sign of Allah’s omnipotence, as the following verse from the Holy Qur’an states:

"And among His signs is the creation of the heavens and the earth, and the variations in your languages and your colours: verily in that are signs for those who know." [30:22]

These external variations reflect internal variations, variations of opinions, attitudes and objectives. This also is registered in various places of the Holy Qur’an. Here is an example:

"If thy Lord had so willed, He could have made mankind one people: but they will not cease to dispute, except those on whom thy Lord hath bestowed His mercy: and for this did He create them." [11:118-19]

Al-Fakhr ar-Razi comments: "This verse is indicating the diversity in people’s creeds, moral codes and behaviours."

I would like to elaborate about the above verse by saying that had Allah so willed, all humans would have embraced one religion by instinct and original creation (Arabic: Al-Fitrah). But in this case they would cease to be human in the sense we know them – their social life would be something similar to bees or ants, and in spirit they would be like angels who are disposed by creation to embrace truth and obey all that they are commanded to by Allah. There is no room for conflict or disagreement among them. But Allah in His wisdom has chosen to create humans otherwise. They have to acquire knowledge rather than have it as an inherent endowment; they have the volition to choose what to act and to weigh out possibilities and opposites; they are not predestined to behave in a fixed way. They vary widely as to abilities, capacity for acquiring knowledge and preferences.

As for the clause: "and for this did He create them" in the above-quoted verse, it may not be presumed to mean that Allah created humans so that they may disagree – It is known from other texts that what Allah created humans for is worshipping Him. The purport of the above clause is rather that Allah created humans so that there will be among them the group of the well-guided and the group of the misguided, the former destined to enter Paradise and the latter to be punished in Hell.

In addition, the following may be deduced from the same clause: Allah created humans so that they would, because of diversity in abilities and dispositions, choose different professions, and this would make for stability in the world. It is through  humans that Allah carries out His ordinances. Men will employ other men to do work for them (See Ruh Al-Ma'ani, Vol. IV, Chapter 12, p. 164, and Tafseer Al-Qasimi, Vol. ix, p. 182) . There is in the creation of humans the propensity for variation in learning, viewpoints and feelings; this in turn will lead to variation in wills and preferences; and faith, obedience and disobedience are part of that (Tafseer Al-Manar, Vol. xii, p. 194).