It's a little obvious in my case

I'm an aTHEIST.

Theists are anyone who believes in a God.  Religious or not.  It's an all encompassing term.  

On topic, I'm a Christian here.  I avoid religious threads primarily because forums are a pretty rough place to host them.  I will say that, in address to choices, whether you believe your beliefs are a choice or not is all about your worldview.  A purely materialistic (only the physical exists) atheistic worldview carried to its logical conclusion excludes the possibility of choice by nature.

Yep. Although, these religion threads are gonna be the downfall of VGC. JK, but they do create quite a bit of controversy.

I'm christian.

Well, think of your beliefs.  Did you consciously choose them?  If you wanted to truly believe in another religion could you just choose to do so?  If you wanted to be an atheist could you simply choose to be one right now?

Where is the exact difference between being an Atheist or Theist? How exactly do you define believing in the existence of a god? What makes a god a god?

If you believe in the scientific method and that life in form of the genetic code system has been created by someone or something out of our currently known world, are you a theist then?

Hmmm I've been on both sides at some point in my life...so ive been open to both. At the end of the day I consciously choose my believe.

Although id say that this isnt a black and white topic. Everyone is different and will have different opinions on this. I think some have a choice and others dont. It most likely all depends on how strong you feel about it.

OT: I'm christhian.

I don't agree altogether that being atheist is not a choice. It is. In fact, you have to have a lot of faith to be an atheist. Even Richard Dawkins  - the christhian apologist xD - call himself an agnostic because he (and no one) can be 100% sure that God or gods doesn't exist.

I'm not judging it. I'm just saying that, in my opinion, it is a choice.

Muslim here as well