I used to believe religion is the scourge of the 21st century. And that if all of mankind turned atheist, most of the world's problems would disappear. Religion is the root cause of most of the hostility between nations, which manifests itself in the form of war. These wars consume a disproportionate percentage of those nations' resources, both human and monetary, thus, depriving their populations of those resources, consequently, leading to unhappiness and deterioration in living standards.
But now, I feel the problem is deeper than mere religion. The root of the problem is communalism in the classical sense of the word. Man seeks comfort in numbers, forming communities to achieve that objective. Classic examples of communal groups : organized religion, racist cults, countries.
These communities turn out to be exclusionary in nature with an inherent potential for the generation of inter-community rivalries. Secondly, man is an egotistical beast. Due to his delusions of self-grandeur, he tends to regard his own community as being superior to others. Once other communities have been deemed inferior, then it is just a matter of time before the destruction of their members ceases to be deemed immoral. In that scenario, killing the member of a foreign community is viewed to be as sinful as, say, killing an animal. For example, kill a fellow countryman, you are a murderer. But in a war, kill an enemy soldier and you are a hero.
There really is no difference between these varied forms of communalism. Consider what happened in the wake of the cartoon controversy. Iran, out of religious spite, decided to rename Danishes as "The roses of Mohammed". And compare that with what happened in a so-called developed country like the US after France refused to be a co-invader in Mission Iraq. French fries were renamed "Freedom Fries" out of nationalistic passion. So is there any difference between religion and nationalism? Not really. Religion uses the illusion of a morality-conferring Supreme entity called "God" to justify acts of evil, whereas nationalism uses the illusion of a Supreme entity called "The Country" for the same purpose.
Which is why I do not feel that the eradication of religion would affect, in any significant way, mankind's onward march towards ultimate extinction through self annihilation. Religion might disappear through the spread of science, but humans will always form communities since forging communities is one of man's primal urges. And as long as there are communities, there will always be communal warfare. Today it's Hindus against Muslims, Arabs against Christians. Tomorrow it could be plumbers against vending machine repair technicians. And the day after that, the white haired fogeys versus the bald seniors. Mankind just needs a reason to divide itself and destroy the other side and religion is just one of the many mediums through which this division occurs. Which is why, even though I am no less opposed to it today than I was yesterday, I understand that there are factors other than religion that are responsible for mankind's downfall as well.
In conclusion, I hold no hope at all for the future survival of humans as a species.