Why Is Atheism So Loud

A definition is the most ridiculously irritating way to start a book. Most authors who have tackled an issue have this annoying habit of defining their subject on page one. If I were the standard author I would start with something like, "what is atheism?" I'm going to skip this stupid practice of intelligence insulting because I assume you already know what atheism is. If you don't know, call your local plumber and have him rap you on the head with his pipe wrench, because you need to have your brain rebooted. If you've somehow missed out on the new atheist movement that has been publicly blood letting Christian culture for the last 30 years then maybe this book is a little too heavy for you. I'm going to try and stick with things that you might not already know but might like to.
Atheism has been around a very long time. Although ‘atheistic religion,' may seem like an oxymoron, that is what is found in some parts of India before 500 BCE.⁠1 Even the ancient Greeks, who were more religious than my Great Aunt Bertha’s pastor, had threads of atheism running through their society. Modern atheism had its origins in Ancient Greece.⁠2 The first well-documented set of atheistic ideas began to trickle out of the sixth century in the writings of Xenophanes, when he said, if horses had hands, then horses would draw gods that look like horses.⁠3 This sounds like something you might find in a Sam Harris or Richard Dawkins book. Xenophanes was not an atheist. However, his words began a dialogue that continued through the following generations. 
 Through the ages, philosophers and writers like Democritus, Euripides, Aristophanes, began to pry the door open to allow atheism to enter. The modern atheist writers, whose names I don't need to recount to you, stand on the tradition of these ancient poets, play-writes, and philosophers. The word "atheism' appears in English books at least as early as the mid-1500s,⁠4 but atheism did not emerge as a recognized belief system until around the 1700s.⁠5  
I mention all this to let you know that Atheism is not new. There are those that have debated me personally who have claimed that atheism is a kind of  ‘next step in human evolution.' If it is a step in human evolution I would ask, why then have we seen all of the world's major religions crop up and flourish in the time that atheism has been present? Instead, modern atheism should be seen as one of many philosophies that humans have tried. Traditionally atheism has had a very low rate of acceptance and continues to even today. Encyclopedia Britannica estimated that the number of atheists worldwide was around 136 million in 2010.⁠6 That means that only about 1.9% of the world population were self-identifying atheists that year, and the number has continued to hold somewhere near that average.
If you're like me the fact that 2 out of a hundred people are atheist leaves me wondering, why is atheism so loud? I spend a lot of my work life online. It seems that hardly any day goes by that I don't see some atheist content. How is it that atheists can permeate such a wide swath of the online landscape with such a low number of people?  I think the best answer is simply, ‘copy and paste.' Copy and paste makes the 2 in a hundred crowd of atheists able to present a Goliath presence with a David-sized population. If you have atheist quote mortar shell lobbed at you as often as I do then you know the feeling. 
Here's how I deal with the ‘copy and paste' noise of atheism. I search out the source of the quotes. There are plenty of great apps online that allow you to do this. When some stranger throws a 1000 word tirade at me, I try to find where it came from, because I generally assume it didn't originate with the person that is currently posting it. What I've found is that outspoken atheists have a habit of repeating other atheist's words a lot. Rarely is there any indication, in these forums, comment threads, or message boards, that a quote is stolen from another person. Even though this is called plagiarism, it hardly seems important to these evangelists of atheism. 
I recently brought this subject up with an atheist who was spitting hundred line anti-God tomes at me. I quickly found the blog where he had copied it from and asked him about it. He replied, "why does it matter?" I told him, very kindly, that I'd like to hear his thoughts, rather than the machine gun fire of atheist ammunition with which he was blasting me. The conversation ended shortly after, but not by my desire.
Searching out atheist quotes is like digging up rabbit holes. I recently spent an afternoon, working my way through the bibliography of a well-known atheist blogger. After a few hours, I found that the works cited in the bibliography were the blogger's own self-published books. The blogger hid this behind various double layered citations, pseudonyms, and other methods which probably were intended to add a sense of credibility to the bibliography. This well-known atheist blogger gets quoted a lot in online debates. I had to laugh to myself. Because of this and many other similar experiences, I've coined a phrase, ‘circular citation.'7
I don't have the countless hours needed to determine if this applies to every atheist online, but my experience is that it's very common. I have a few atheist friends who don't do this, but it's because they are very smart, and in my opinion are searching for the truth. The atheists that don't employ ‘copy and paste' like it's a full-time job are less interested in winning debates, and more interested in the reality that religion may or may not describe. 
In addition to ‘copy and paste,' I think there is another answer for why modern atheism is so loud. Many are pissed off. This is the common trend for those who find themselves in fiery online arguments. I think for most human beings, arguing is considered distasteful and mostly avoided. For those that are motivated to do it, they must have ample motivation. Anger is a powerful motivator. Many times I've asked atheist debtors about their background story. I've probably received about 35 responses to this conversational background check. Out of those who have responded all but one, as far as I can remember, report being ‘forced' to believe in the Christian faith at some time in their early life.
When parents, youth leaders, or pastors pressure young people to believe, there is a consequence. A certain percentage will escape violently like the shrapnel of a grenade. As they do, they often seem determined to maim others in the process. It's valuable to recognize, if you are a Christian and find yourself in this situation, that you should listen more than you talk. I've found that angry people need someone to listen as they vent their frustration. If you're a Christian, you represent the community that oppressed them, and therefore, ‘you'll do.' In these situations, stay quiet, and listen relentlessly. At some point, you may get a chance to respond, but if you respond when someone is only angry it can do more damage than good.

1 Pandian, P.S.K. “The India, That is, Sidd.” (1996): p. 64
2 Baggini, J, ‘Atheism: A Very Short Introduction.’, 2003, pp. 73-74
3 Barnes, J. “Early Greek Philosophy.” books.google.com (2001): p. 43
4 Rogers, DMG. “English Recusant Literature, 1558-1640.” books.google.com (1979): p. 51
5 Baggini, pp. 73-74.
6 Turner, Darrell J. “Religion: Year in Review, 2010.” britannica.com, Encyclopedia Britannica. (2010)
7 Circular Citation is when an author only quotes his own previous work to support his own work.