I don't believe in God, or god, or gods (I surely can't believe in more than one if I don't believe in one, right?). Do I know there is no God? Well, yes and no. I know it with the same certainty that I know I will wake up tomorrow morning, that the sun will come up, that I won't get hit by a bus the next time I cross the street. Can I say with absolutely certainty that there is no possible way I can conceive that I could be wrong? Of course not. But, for sake of this rant, let's say I know there is no god (I won't capitalize it since I am not afraid of offending him/her/it).
So, I guess you would call me a strong atheist. The 'believer' will ask: "how are you so sure?" I could ask them the very same question of their belief, but that comes down to faith, which means believing in something for which you have no proof, so that seems like a fairly useless endeavor. The reason I 'know' there's no god is because there is no NEED for god. The universe is a very ungodly thing.
If there were a god, why did he/she/it feel the need to create such a massive universe that continues to expand? Leg room? Why would he/she/it make the universe so old (13.8+ billion years)? Leisure time? What is the need for the birth, life and death of so many trillions of stars over the history of the universe? A good fireworks show? We know through observation and modeling that stars are born from clouds of gas that are compressed by gravity and heated to the point of fusion. No need for god there. We know that the heavier elements in the universe are the remnants of explosive stellar deaths; that all the iron and carbon and sodium and nitrogen and other elements in our bodies is literally star dust. Why would that be the case if god could just "poof" humanity into existence?
The believer responds: "you just can't understand the mind of god." Well, that's true. But, I've been high and that's close enough. The believer might say, those things don't mean there is not a god, he could have created the universe to act that way. Well, sure. And monkeys might fly out of my ass tomorrow, but I am not betting on it. Why would an all-powerful, infinite being create the spectacle that is the universe, a system that continues to grow, giving birth and bringing death to stars, creating massive-gravitational light-sucking vortices called black holes and all sorts of other bizarre and seemingly unnecessary cosmic oddities? Is the believer's god like a three month old easily distracted by shiny objects? Ohh, look! A supernova! Wee!
(BTW, I am not even going to address those believers who think the earth is 6 or 10 or 15 thousand years old and cavemen rode dinosaurs. Those f**king idiots barely generate enough brain function to keep their vital organs functioning, so I will leave them alone out of humanistic compassion.)
The believer's god could be something like the mechanic who put together this grand machine (the universe), turned it on and left the building without flipping the off switch. In that case, the universe was set up by this god to be a self-sufficient and continuous system. It still begs the question: why build it? What purpose or reason would an all powerful, omnipotent being have for the universe? A great vacation spot on the surface of Jupiter? When you're infinite, vacation time is meaningless.
The believer might argue that the mechanic didn't leave - he's still watching his grand machine, tinkering with the dials and knobs. Really? On what do you base that? What evidence is there that the hand of god has intervened into anything, at anytime, in the course of human consciousness (if you mention the Bible/Torah/Koran, I will slap you) or even prior to that? The believers assert, with no foundation other than their faith, that this grand mechanic answer their calls (prayers) for repairs (in the form of miracles). Really? For every 'answered' prayer, there must be millions, maybe billions, that go unanswered. Is that beyond the realm of chance? Not by a long shot. If a million people prayed, and one prayer was 'answered', believers would cite this as evidence of god's power. But what of the 999,999 unanswered prayers? Why does the mechanic ignore so many more requests for repairs than he answers? He must belong to a union.
If god created the earth, why dinosaurs, Pangea, ice ages? None of these did anything to benefit humanity, for which our planet was supposedly created. And what of life on other planets? Did 'little green men' get a little green Jesus (or Mohammed, or are they still waiting for their little green messiah)?
Believers argue that the fact that everything in the universe works so perfectly is 'proof' that there was an intelligence in its creation. This arguement is stupidity wrapped in retardation. The universe works perfectly in the sense that it actually works. If it didn't, we wouldn't be here to ascribe god's hand to it. It works the way it does because it has to work that way. It follows the laws of physics (some of which we still don't fully understand, such as the mechanics of gravitation). If there was a creator's hand involved, it wouldn't need those laws. It could work in anyway that creator desired. The same goes for evolution. Our hand works well because it works. If it was detrimental to our existence, it would have been selected out through evolution. Adaptations that work, even if only marginally, survive over traits that do not work. If a creator had designed humanity, why not give us umbrella heads to keep ourselves dry in the rain, thick fur coats to withstand winter, etc. There would be useful, if not necessary, traits a creator could provide that would make a lot of sense. And yet, we have the bodies and brains that we have simply because they are adapted to the needs of our world. No matter how helpful it might be, humans have relatively little body hair because the climates in which we evolved didn't require it.
There isn't a single example where something exists that doesn't make sense in nature/physics and can only be ascribe to an intelligent creator. Not one. While there are things in the universe that we may not yet understand completely, it is science, not faith that will give us the answers we need.
While there are certainly writers who make better arguements for strong atheism than I (I'm looking at you, Richard Dawkins), I just wanted to make my points and defend my view from the swirling cesspool of stupidity that has bubbled to the surface of our public discourse.