Why do people care what other people believe?

Firstly, you've assumed that everyone can merely choose what they believe. From this we can deduce that you are able to and assume everyone can, but actually that isn't the case. Rational people cannot choose what they believe, even when presented with a comforting myth which is conveniently unfalsifiable. They realise that a beliefs desirability if true is still no measure of its validity, and that anyone who can simply "choose" their beliefs is almost certainly deluding themselves.

Secondly, you have confused two different things in your question.

You started off by talking about people's beliefs, then ended your question talking about people making claims about what is true.

My answer requires that you accept the distinction between the two, since I could not care less about what people believe, but the second they try and claim that ridiculous things are true, they can expect those claims to be scrutinised, tested and if ridiculous, ridiculed.

Hate to break it to you, NO ONE should get the monopoly on what is claimed as true. Religions enjoyed that privilege for many centuries, those days are gone, and rightly so.

The Libs,who are most likely not real Christians,if at all give out the stuff to the 47%ters

Those people are trying to help people. You may call it mental illness or not, but these people actually believe that Atheists are going to Hell. They care about people. They think they are trying to stop Hell.

I'm a Christian I always tell:

people have the freedom to believe what they want, and to do what they like, as long as they don't hurt anybody

so anyone has the right to be an Atheist

because being Atheist doesn't hurt anybody

I care cause religion one day could kill other people.

Though i'm usually fine as long as they don't shove it down our throats.

I don't really care if other people want to believe in god or gods. What I care about is that these people seem to think they have some right to inflict their beliefs on me by way of outdated and sexist laws, or indoctrinate my children with their beliefs through the education system. I care that they feel the need to knock and my door and tell me I'm going to hell. I care that they think I can't have morals because I'm an atheist.

So basically I care when people are douchebags about their beliefs.

Because each religion assumes their own should shape and influence culture, education, law, public policy and social attitudes. As such, each is inherently based on a cornerstone of inequality.

As a human being, I believe in the advancement of the species through the building of commonality amid diversity rather than championing division and misplaced superiority and conflict.

With this in mind, while tolerant of people's private individual beliefs, I will always champion a secular framework for society where common sense and decency are valued more highly than one faith, or another's, special book.

I care about others belief because I want to learn. Learn new ways of looking at the spiritual life.

the only problem is that as soon as I show a bit of interest - they all want to convert me.

which is not my intension.

It seems like people feel more safe if everybody they know are just like them - believe the same way.

As usual in our behaviour we must look at evolution. It makes sense that we have a psychological drive to inform people of "How things are". It surely must have helped us as a social species.

“Theists, especially Christians, try to control and restrict us based on their views.

If all Christians stop crusading against science, education, culture, art, sex and sexuality, religious freedom and such, stop dishonestly misrepresenting your beliefs as facts, and stop telling everybody else they're going to be tortured throughout eternity unless they join you, I assure you that you won't encounter nearly as much hostility.”

‘Religious apologists complain bitterly that atheists and secularists are aggressive and hostile in their criticism of them. I always say: look, when you guys were in charge, you didn’t argue with us, you just burnt us at the stake. Now what we’re doing is, we’re presenting you with some arguments and some challenging questions, and you complain.’ A.C. Grayling

‘There once was a time when all people believed in God and the church ruled. This time was called the Dark Ages.’ Richard Lederer

“Radical Muslims fly planes into buildings. Radical Christians kill abortion doctors. Radical atheists write books.” Hemant Mehta