I find it quite amusing when I encounter believers who challenge my right to speak out against their beliefs. They usually state their question in the following manner: "If you don't believe in God then why don't you just leave the matter alone and let others believe what they wish?" Let's see what the 1st amendment of the U.S. Constitution has to say about that.
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
If we break this down the first thing theists need to notice is that this sentence is broken down into several parts by the use of semicolons. Right after the part about laws respecting religious establishments and the exercise of those religions we come to our first semicolon. This second part is the part that is relevant to this post and will answer your question. Congress will not abridge the freedom of speech or of the press.
What do they mean by abridging the freedom of speech? Well according to Encarta via Bing search there are three meanings to this word, but I am only interested in one: "restrict somebody's rights: to deprive somebody of rights or privileges"
As you can see that by the very same 1st Amendment right that you declare your right to practice, preach, and proselytize your beliefs I too have the right to not believe, oppose, and and expose it. That's right! The 1 Amendment wasn't just made for Christians alone this right is for everyone in these here United States. That includes the Buddhist, Mormons, Christian Scientist, Satanist, etc.
It's not wrong to ask why should I when faith does not suffice. Not everyone can simply accept a worldview or new belief sets based on faith without requiring evidence. When I first accepted that I was an atheist I was afraid to make my stance on religion known. I would let theist corner me on the streets and subways and listen to their endless drivel, and thought that by doing so I was respecting their beliefs. The reality was that I was depriving myself of my right to reject their beliefs openly in the name of unearned respect.
On one particular day I was walking down the street and a theist approached me ready to bombard me with Jesus. Something in my head snapped and I came to the realization that if they want my respect they should respect my views as well. As soon as he opened his mouth I blurted out that I was an atheist and was not interested in what he had to say. The next question that usually follows always baffles me. It's the old why or how could you not believe in God. If I am in the mood I go for it, but if I am not I feel that it's none of their business why I don't believe in God.
If you think about it we don't go around asking theists probing questions as to why they believe in God without evidence. Online in a debate is an entirely different situation since theists and atheists alike are both willing to engage in discussing their beliefs or non-beliefs. Imagine if atheists went door to door proselytizing! Imagine that when we encountered believers that we would drill them on why they believed. I've had this happen to me in person with the Jehovah's Witnesses and street proselytizers many times. As if I owe them an explanation for not believing in God! Just like their claims of absolute knowledge their arrogance disgusts. me.