I am just surprisingly overwhelmed by the number of athiests and agnostics on Christian Forums. I'm not hating you for it, go head, do you! I was just wondering...why?
With the possible exception of a smattering of isolationist countries, religion has an influence on the history and culture of almost every society, and on the daily lives of virtually every occupant of this planet regardless as to whether or not they are religious. One of the commonalities with the majority of human civilisations throughout mankind is the establishment of some form of religion. Everyone has wanted to know how we got here, why we are here, the meaning of our lives, and what happens after we die. The same basic questions that were asked millenniums ago are still relevant today, and religions all have their own way of answering them. I think basic human curiosity could lead some people here, just to exchange viewpoints and perspectives and ruminate.
Since Christianity has permeated much of the Western hemisphere for centuries and is still a dominant force in many countries, I think it's natural to specifically want to talk about it if you live here. Christians have influenced laws, policies, perspectives, attitudes, and cultural habits that affects everyone, in small ways to significant ones. I was just in Germany where 95% of the stores are closed on Sundays, despite it now being a predominantly secular country now, because of longstanding traditions dating back to the Christian sabbath. It means that if you're an atheist, an agnostic, a Buddhist, a Christian, or whatever if you haven't stocked your fridge and gotten your prescription medications and all that jazz before Sunday, you're outta luck. Now I'm in the UK and apparently they had similar regulations for decades up until the 90s. In the US, the influence is more palpable with it reaching into science, public education at all levels, medical care, and even personal civil rights. I can understand wanting to offer insights and opinions on topics relating to religion when it's so relevant to so many facets of your life and those surrounding you.
I also think it's reasonable to want to provide counterpoints to many of the societal stereotypes about atheism. In your full OP you stated that you don't believe in Buddha, Allah, or other supernatural deities, but to what extent does your disbelief in them impact the culture where you live and how you are treated and accepted by others who live there? Your flag lists you as being in the US and a Christian Republican. You are going with the grain instead of against it, so you probably haven't felt the splinters many who are atheists in conservative Christian communities have gotten. One of my friends who has been an atheist her entire life recently moved to the South because of her parents' work, and suddenly began encountering all these hurtful misconceptions and attitudes that she never experienced while growing up in NYC. It became so relentless and distressing at her public school she switched to OSG (Online School for Girls). Others who've had similar experiences might be drawn to come here and discuss them, perhaps to vent, and perhaps with the hope that they can meaningfully alter some of the mindsets Christians have towards atheists. This site is publicly viewable, one of the largest forums on the web, is featured on popular channels like Real Actors Read and FSTDT, and therefore a logical place to address issues atheists have faced from Christians both online and in their personal lives.
It's also possible that people came here as Christians and over time their religious beliefs changed and they are now atheists. In the teen section someone who is now an atheist commented on a thread she created a couple of years ago when she was a Christian because she was stunned by how much she'd changed. When I joined here last June, age 16, I classified myself as a Christian, but am simply going with other-religion for now because my beliefs don't seem to fit within the bounds of the connotations for the labels here. Anyways, it's not like this is a site exclusively for Christians and atheists are just sneaking on here. The site is open to everyone, and atheists are honest about identifying themselves as such. Most I've interacted with actually seem to be nicer, more reasonable, and more reliably mature than Christians their same age. Personally, I'm glad atheists, agnostics and humanists are welcome here because I've learned more from them, especially in regards to science-related issues, and enjoyed their contributions.