Even with all these diverse cultures, religions, races, languages, people end up having the same needs and wants. Everyone is looking for happiness, self-fulfillment, and a rich (and by rich, I do not mean monetary) life. Though we are all unique individuals, we all strive for the same goal, a good life worth looking back on.
Not everyone can follow the same path to the 'ultimate' goal of true happiness, and I think this is a fact that is all too often forgotten. Some need religious, or spiritual upliftment, and others find more comfort in rational thought and logic. Those that try to comform destroy their ability to find themselves; unless that is what they truly want, but then they should not judge how others try to discover their own place in the world. Discovery is part of the mystery and wonder of the world. Everyone should have the right to be different.
I have tried my best to understand prejudice, and how it works, but found the old answer of: "if you are not comfortable with yourself, then how can you accept others", to be the best answer so far. I have many friends from diverse backgrounds, some have been subjected to racial, to gender, to sexual, to cultural, to language, to religious, prejudice. To me, they all come from the same place, insecurities with ones self. If you are truly comfortable with yourself, why would you be afraid of the 'other' (and I mean this in the form of the 'other' being people who are not like you). I may be a little bit of an idealist, but I cannot see why people cannot learn to enjoy, respect, and live with each other.
Some people will say that it is the way they were brought up, but I find that a poor excuse. People are able to learn, so what makes it so difficult to actually find out. You have the right to be an individual, and so make a choice to enrich your life and educate yourself about other people, and in the end find out who you truly are.
The only prejudice you should have is the one against prejudice.