Eyepopper made the best contribution to this thread. Most of the awful things in this world are done for power and money (oil, resources etc). Religion may be used as an excuse by some extremists, but they're not the ones making the powerful moves in politics that leads to most wars. The world wars were not started by religion. Exploitation, greed and individualist selflessness cause most of the world's harm (incidentally, those are the things that most religions argue against!)
As a feminist, I hate what the Abrahamic religions have done to women, and am in favour of getting rid of them as much as possible - the laws against contraception and abortion are causing untold harm, but women have been subjugated by secular states just as much. A lot of secular people still don't believe in abortion, and plenty still believe in 'traditional' values that limit women's rights to contraception. Capitalism in general subjugates and oppresses women. Atheist philosophers and thinkers have been extremely misogynistic in the past, and most of earlier ones still argued in favour women's inferiority (*cough* Freud!), it took more than just eradication of religion to bring about women's liberation, it took a complete change in attitudes, and the attitudes of the early atheists had to be changed as well. The same is needed to bring about a change in the way our profit-driven world exploits and harms the majority so the minority can make money.
Incidentally, the 20th century was probably the least religious century there's been since the beginning of civilisation, and was also probably the most violent century of all. I'm not saying secularism causes violence. But to eradicate violence and oppression takes a lot more than just getting rid of religion, because I think greed and exploitation are bigger causes of inequality and harm in this world, far more so than religion. A more egalitarian society would bring about the utopia the atheists in this thread want, but it's going to take completely changing the mindset of the people, and that won't be given to us just by getting rid of religion.