Trigger words: Religion religion
Indicator sentences: Reading some of your replies, it is apparent that you equate "religion" with a series of beliefs, which you define as "ideas" which exist in someone's mind and can be relegated to that space. This is indicative of someone raised in a western Christian culture, where religion actually is little more than a list of concepts and doctrines to which a person claims to hold. There is a very strong history of rationalism in western culture and religion in the west has, at least since the Enlightenment, manifested itself as a world of ideas rather than practice. There are lots of reasons for this, but it is important you understand that distinction. Religion, as you understand it, is fundamentally different from religion as much of the world understands it. Your understanding is also vastly different from even the understanding of Christians as recently as the 14th and 15th centuries.
Negotiation parts: For most of the world, religion is not a series of ideas or beliefs as much as it is a practice or identity. People don't so much "believe" in the western sense as much as they simply "are" and religion in this sense is understood as the basis for all they do. As an example, look at Indian Hindus. Their marriage traditions, familial kinship, friendships, and every significant aspect of their culture revolves around the Hindu pantheon. If you've ever spoken to the average Indian Hindu, though, you quickly recognize that their devotion to their faith doesn't stem from answering questions or providing purpose to their lives. Instead, it is a framework of existence through which they view all other things. It's their very soul. Christians were like this as well for many centuries and still are in eastern Christian churches, but in the West, the wars of religion, protestant reformation, and subsequent periods have left a mark on the very meaning of the word "religion", thus clouding your view. The ideas which inspired those laws providing special protections for religion were devised, at least philosophically, during a period when Europeans were tired of people warring in the name of God and using the Christian religion to manipulate the masses. They weren't intended to provide protections for the drooling hordes that go to fundamentalist megachurches, sing kumbaya, and then listen to a motivational speech on how much a deity loves them for being themselves. Those protections exist for the rest of us, who are marked by our religious beliefs, can't be anything but what we are in the context of our religion, and refuse to elevate any political theory or social concept above it. I am not religious because I believe it. I believe it because I am religious and through that lens, all that I see, think, and do is affected. Most people like me can't change that, so we deserve to be protected from those who think it is all just a game of ideas and those who might hold an entirely different religious framework. It keeps the peace. This is possibly the most important reply here. The way the Western world understands the concept of 'religion' is rather historically unusual, and a great deal of the rest of the world understands it in a different way. The OP compares "I believe in X and Y" to "I like red cars", but the problem is that religion is a far wider concept than just "I believe in X, Y, and Z...", especially outside the Western world. This makes it a lot harder to compare with things like "I like red cars". The turban-wearing guy in the OP's example is not necessarily a case of "I want to wear this turban to work *because I hold a belief in X*." In reality, it would be more like "I want to wear this turban to work because my entire way of perceiving and interacting with the world is completely bound up with it"