I am an atheist, so when I use the word God, I am referring to others' belief systems.
I don't understand how critical or confrontational approaches are going to make anyone change their mind about God. Believers try to point to “proof” of God. There can’t be physical proof of God because God is supernatural. Anyone who points to physical “proof” has, by definition, come up with a NATURAL phenomenon - which CAN’T be God. Conversely contributors on atheist sites quote the Bible to try to convince believers that the Bible is wrong. Both perspectives are equal wastes of time.
People who try to DISPROVE God are silly because believers don’t NEED proof to believe in God - that’s why they call it “faith” and not fact. "God is a mystery" is explanation enough for them.
I used to favour just leaving believers to their own illusions. I decided that it’s a good idea to “propagate” atheism when President Bush told us that he’d talked with his good buddy, God, and God said his invasion of Iraq was a good idea.
The place to start this “propagation of the fact” is to try to understand why believers believe as they do. And there are some VERY GOOD reasons. Atheists don’t like to deal with the fact that the vast majority of humans believe in God - except to maintain that they’re all stupid - not so useful.
Primarily, believers are children of believers. All their lives they’ve been told to ignore logic and to love God with their hearts. HUGE emotional weight is brought to bear from almost every quarter - parents, schools, clergy, etc. All their lives they’ve been taught to fight all “impure thoughts” - any fleeting doubt, any crack in faith is beat down before it can gain any roots. These habits are not easy to dismiss.
Secondly, psychology plays a very important part. In fact there are good, natural reasons for such a belief. The natural universe is so incredibly complex and intricate - from the motion of galaxies to the structure of DNA - how COULD this be an accident. Only in the last couple generations (a mere anthropological heartbeat) have humans STARTED to come to grips with the HUGE expanses of time in which the “miracle” of natural selection can actually make sense. (The vast majority of humankind cannot, still, even come close to comprehending these time scales.) The advance of science and the general understanding of science by humankind has resulted is a corresponding increase in atheism. Yes, this universe CAN be random; and all the "order" we see is simply the laws of science at work on these random events.
Thirdly, language itself is, in my opinion, the father of God. I love the opening line of the Book of John: “In the beginning was the word, - and the word was God.” "The word" - language. Just as you can’t have left with no right; up with no down, a beginning with no end; you can’t have a speaker with no listener. These two concepts are the two halves of language. They’re what language is made of. Add to that the fact that words are forever flowing through the minds of all people. All people, therefore, have two individuals in their heads at all times - a speaker and a listener. We are only ONE person – where is the other? So we quite naturally (and with help from religions) call one of these individuals, “God”. God is ALWAYS listening. God knows EVERYTHING we’re thinking. God can speak to us and we can speak to God at any time.
What’s harder to accept is that BOTH of these individuals is really YOU (and the nature of language). It’s an almost magical illusion. And billions of humans are prepared to (maybe even wired to) believe in magic at some level.
And there's another by-product of language. Everything has a name. This gives us the illusion that everything has an answer. Show us something, we'll give it a name. Show us several, we can count them. What doesn't fit well with language is the idea that there are things most cannot comprehend – like the infinity of time and space. If there happens to be something for which we do not have an answer, there must be an answer somewhere, and someone must have this answer. This is one of the most prevalent logical fallacies "proving" the existence of God to many. The simple statement, "I don't know." is where God ends and science begins. Religion cannot accept "No one knows", science can. In fact science is delighted with this answer. Even when we discover things which are inconsistent with the science as we know it, science is perfectly happy to change to accommodate this new information. Religion, being from God, by definition cannot change. So the words God gave us thousands of years ago, cannot, by definition, have been false. Yet the more society learns, the sillier these words are if taken literally. These words are simply a reflection of how these semi-nomadic herders saw their world and their society thousands of years ago when they knew virtually nothing about nature.
There are, however, a LOT of good lessons in these "holy" books. The most striking of these is the power of love to bring happiness to people's lives. Add to that the power of greed (the opposite of love) to bring misery to everyone it touches.
Lastly, let me tell you about a photo I saw recently. It was all black with white dots here and there and a barely noticeable band of brown through the photo. At a point in this band was a tiny blue dot. This was a picture taken from beyond the edge of the solar system. It was a photo of earth. Carl Sagan said of this photo:
From this distant vantage point, the Earth might not seem of particular interest. But for us, it's different. Look again at that dot. That's here, that's home, that's us. On it everyone you love, everyone you know, everyone you ever heard of, every human being who ever was, lived out their lives. The aggregate of our joy and suffering, thousands of confident religions, ideologies, and economic doctrines, every hunter and forager, every hero and coward, every creator and destroyer of civilization, every king and peasant, every young couple in love, every mother and father, hopeful child, inventor and explorer, every teacher of morals, every corrupt politician, every "superstar," every "supreme leader," every saint and sinner in the history of our species lived there – on a mote of dust suspended in a sunbeam.
What giant forces are there in society which cause people to believe that the fantasies of some nomadic herders near the dawn of their civilization could possibly be of any real importance in this infinite vastness which these herders could not come close to understanding?
Militant atheists think they’re going to change things by saying that theists are not only stupid but evil. While religion has been used by countless evildoers to further evil ends, religion, for the most part has been a comfort to people. God, to most, means Love. Although often misused, this equivalence has given love to millions who might never have experienced it on their own.
Religion, to many, means community. This relationship is so prevalent that finding a sense of community is often nearly impossible without a religious framework. (Maybe that’s why so many atheists are so militant rather than being more accommodating to their fellow humans. :-)
In summary minds are changing and more minds need to change. NOBODY changes their minds in the face of confrontation. People’s views only polarize. Change will only be accomplished through understanding - not bluster.
The problem with “God equals Love” is that too often people don’t understand that Love is just as easy without God. If we want people to abandon useless (and dangerous) fantasies, we must demonstrate that doing so will not represent a net loss in their lives, but rather a huge gain - a gain in love for your fellow human beings.