Why religion is not a private matter

I've read article by atheist software engineer from UK. His most staggering misconception of religion in general is that it's a private matter. This misconception is very common opinion in western countries.

Goal of this article is to explain why religion never was, never is and never will be a private matter.

Making better world

Human beings have in their nature to fix things. To set thing right according to their view of the world, beliefs. If they cannot fix it they at least talk about it. This goes across all religions and so called not-being-religious-at-all atheists as well.

When Christian sees injustice or wrong thing in his opinion. He tries to fix it to improve his world to set up to his standard.
For example Christians view homosexual intercourse as immoral. So what they do. They try to fix it and prevent gay marriages to be sanctified by law. They go around and talk about homosexuality being a unnatural, etc. People argue about it and some are offended. 'Why do you say it? Re: It's not true. We don't want to hear it. It's your opinion don't force it on us and don't shove it in our face. We don't care!'
Same is done by atheists. For example atheists thinks the prohibition of masturbation, sexual intercourse before marriage and anti-conception is unnatural and unhealthy. What they do? They try to establish mandatory sexual education so even child brainwashed by fanatic parents adhere to healthy life style.  Re: 'Why do you say it? Re: It's not true. We don't want to hear it. It's your opinion don't force it on us and don't shove it in our face. We don't care!'
Individual struggle to make better world, to improve is undeniable and unavoidable.

Leaving faith at doorstep

Is it possible to stop being yourself? Asking somebody to keep religion private matter is the very same. Your religious beliefs influence your life, every action. Morale, conscience, etc. those are defined by your world view. Even if your belief is non-belief. Asking Christian or member of any religion to make his religion private matter is asking to stop being theist and became atheist. For most atheist (don't care type) this is simple. It's their natural state. This is not possible for theist and more importantly not acceptable. Not only every aspect of our life is depend on our beliefs, but also society as whole is depended on beliefs of each individual.

I'm right, you're wrong!

Not only that every religion (including godless religion of atheism) is sure it's the only truth, but every individual person is sure of its inner morale codex and universe understanding  superiority over others. That is reason why he was so angry. That is reason why I and You would be. Honestly ask yourself. He then elaborates why he is right and how wrong they are, therefore nobody should stick his nose in his righteous beliefs and others who coincidently share very similar beliefs. Because he doesn't tries to impose his beliefs, surely the righteous, on them or any other person. Except in reality he does and so do others. There is no magic to it. You do it by simply living in society. If you want live in the world where nobody attempts to impose their beliefs on you then live in a desert or on an inhabited island.

Fighting evil

Would you keep silent in face of atrocities and injustice? Keeping silent is not mark of tolerance, but rather cowardice. If somebody is murderer, thief, liar or promotes evil. You (the state) have to force justice and truth on them. In matters that are not covered by law you are obligated to at least tell them. Otherwise they cannot rectify their actions and you are accomplice of their evil.

"Religion is a private matter" is the definition of secularism. It is a morale relativism understanding of church and state separation. Because other religions doesn't adhere to those philosophies they won't obey to their's self imposed rules.