The claim that "God is an almost knowable idea. An idea that can make your life, and the lives around you, better" is misleading at best. What, exactly, makes someone's life better? Happiness, love, money? A person's quality of life is very difficult to quantify. A newfound love of God will certainly make you happier. This is one of the main attractions of every religion on the planet. The community formed by a church can be a powerful force for good in the average parishioner's life. No ecclesiast believes himself to be harmful to his flock. Still, I would argue that while the influence of God may be beneficial to an individual's happiness, it is harmful to our society as a whole. So, is God a knowable idea? Sure, but it is knowable in the same way we all understand the concept of perfection. Yet, perfection does not exist. In my opinion, the quests for God, perfection, and knowledge are one and the same. The closest human endeavor has come to understanding perfection is found in the formula E=mc^2/sqrt(1-v^2/c^2). It is so elegantly simply yet profoundly significant. The fact that so few in our society even attempt to understand relativity is a demonstration of the flaws of mankind.
Instead of looking for truth in an understanding of the universe around us, most people search for a personal understanding of God. They assume that their own frame of reference is enough to understand perfection. This means that their perception of perfection is inherently based on their own cultural upbringing. Their God is based on their own society's inherently flawed understanding of perfection.
The only universal truths I have ever encountered have come by way of science and mathematics. All other truth is subjective. When we base an understanding of God on subjective truths, mankind as a whole will never come to a collective agreement.
If we cannot agree about our understanding of God, the natural impulse is to fight about it. Religion is easily the most prominent cause for warfare on the planet. When an individual believes himself or herself to understand the ultimate truth of this world, it is only natural to believe that all the problems of this world stem from the fact that most people have not yet discovered it. The next logical step is that when everyone inevitably does understand this truth, we will somehow enter into a messianic age of peace and prosperity.
Unfortunately, this runs counter to almost all of human experience. From the Middle Ages in Europe to the communism in the U.S.S.R. and China to the dominance of Islam in the Middle East, the more prominent a single unifying ideology is in a society, the less productive it seems to be. Human society is at its most productive and prosperous when we argue, but do not fight. The better we are at questioning and debating our beliefs, the more likely we are to make progress and find truth. This is what led to America's quick rise to prominence in this world. The conclusion I draw from this is that if there is a God, it does not want us to believe in it.
In my life, I have met many people who are devoutly religious and few atheists. I find it very telling that atheists seem to congregate at a website like this. As a whole, atheists have been by far the most prosperous and happiest people I have had the opportunity of interacting with.