Why should one oppose religion? Why should one be an atheist? Here are four brief reasons why one should not only be an atheist, but an atheist who opposes religion.
1. Religion is factually erroneous.
Religion is factually erroneous, which is something that affects all religious people and also irreligious people in places like America and the Middle East. It is knowledge that has propelled humankind forward, civilized us, and improved our lives. Living in delusion is never good and while many would argue religion offers hope, it is false hope; also, religion is like a drug, something one only thinks one needs if one is already hooked on it.
2. Religion indoctrinates children.
Indoctrination is used to make children believe factually erroneous religions, which ruins the critical thinking of these children in at least that domain. In a sense, these children are hooked on a comfortable drug that lets them avoid reality, which isn't always so pretty. Many individuals manage to break through this indoctrination, as they grow up, and this is an impressive feat of which they ought to be proud.
3. Religion has adverse effects.
Religion directly and indirectly has many adverse effects. This can be everything from oppressing LGBT to suppressing science to giving people hubris to suicide bombings. Of course religion doesn't solely have adverse effects and of course not all religious people are murderous bigots, but religion has still had plenty of adverse effects and the final, fourth reason makes religion wholly unneeded.
4. Religion is superfluous.
The beneficial effects of religion—like community, charity, and hope—can easily be achieved without religion. Seeking connections and altruistic behavior are properties of humans, not religions. A world without God doesn't need to be bleak; there's still plenty of kindness, friendship, love, and hope. Religion is superfluous; the universe is amazing enough.