Tolerance is inherently moral and necessarily social. And it can only be applied to people who are different, people you wouldn't consider part of "your" group. It is taught, a developed moral characteristic that may become part of who you are. We aren't born tolerant though, and that is why so many groups of influence have tried to develop this concept of group. Fascism itself is based on it. Our natural intolerance spreads as the worst virus if there are no forces to put an end to it. This is what sociology, so far, has been able to appreciate in the concept of tolerance at a macro-social level, and it has its reasons.
If tolerance is not natural to us, but rather "homophily" (the preference of those with similar characteristics: race, socio-economical class, ideology, etc.), then tolerance is a trait that we can only develop through education, and only if we find it any useful or right.
In the Qur'an it was already pointed that we were created in different groups:
"O mankind, indeed We have created you from male and female and made you peoples and tribes that you may know one another." (Surat al Hujurat)
So I can just expect that for an early Arabic society this indeed meant a call for tolerance for a religion that was going to spread across many nations. It was useful. However, nowaday, this is not what we, as individuals, face. Living in a globalized world, being connected by the Internet and its very own culture, tolerance seems less and less necessary and useful. Ideologies and groups compete between each other, and a call for tolerance is against the efforts to reinforce that feeling of group. It isn't useful for many. Not to mention that tolerance is a highly difficult trait to acquire, as it requires great efforts of empathy. Ask yourselves to which point can you accept the different? And I don't mean their mere existence, most don't care about that. I mean tolerating someone different that is part of your life, in some way or another. We have always been taught to be tolerant when it has been useful, but not because it is good, because it is morally right. Because it is not among the interest of any group of influence. Groups, as the master of history and sociology of the Muslim world once said, Ibn Khaldun, have only one goal: power.
That's why, even revolutions, that are supposed to be the fight for ideas, end up in some sort of fascism and/or dictatorship. Even when the people that lead them truly wanted free elections (modern history is full of examples of this, it is something we can't avoid). They are still necessary, though, for the progress of ideas.
What happens, however, in our societies? In the West, tolerance has been imposed as something useful, but racism, mysogyny, LGBTphobia, etc. are still realities that many people even hate to discuss (many people attack feminism, for instance). In the Muslim world, tolerance died centuries ago, and an enormous amount of groups appeared. We are still reinforcing through our culture this intolerance, based on unreasonable discrimination: country of origin, skin color, studies, amount of money, gender, sexuality, beliefs, family/tribe name, etc. You can realize this inability to accept the different for instance in the topic of marriage, at what type of characteristic will people, parents, or ourselves if we have sons or daughters to marry, will look at. And it's not always the obvious (like don’t be racist). It is usually ideological. We can't accept other mentalities because we weren't taught about that, because the group we belong to doesn't want that.
Tolerance isn't only about accepting black people, or trans people, or seeing women as equals. People will probably try to appear as tolerant in that sense, because it is useful for them. However, as a moral trait, these people are not genuinely tolerant, but conveniently civilized. Real tolerance is being able to respect others by their opinion, beliefs, lifestyle, and of course, biological circumstances. Accept them as long as you are not tolerating the intolerant.
This conflict is paradoxical, and it is a well known paradox in social sciences (originally proposed by Karl Popper). The problem with tolerating the intolerant, as I said at the start of this entry, is precisely how fast and easily their intolerance spreads (because it is natural). As individuals and iA as free thinkers, we should fight to develop tolerance within ourselves and condemn intolerance even when it is present in those people who are part of "our" group (be it our racial "group", ideological, whatever). Intolerance isn't a joke, it's a social human and moral issue of high importance, and has always shaped our destiny.
Thus, I can only advise my readers to dedicate some time to observe that aspect of their hearts, if they behaved in a tolerant manner, identify our errors, ask for forgiveness to the Most Merciful, and ask him to guide us and make us more aware of being tolerant when we are, again, tested in life. Remember to ask Him to guide me as well, iA.