Someone asked Philosophy professor Dr. Peter Boghossian, author of A Manual for Creating Atheists, what his goal was in promoting atheism.
His response was fantastic (beginning at the 2:18 mark):
Every time you bring in faith into any equation, it makes problems more difficult to solve. It’s just removing one trenchant variable, one variable, that will lead us to make decisions that are based upon reason.
If I can make a small contribution… to help people out of these beliefs about talking snakes and Garden of Eden and… people flying to Heaven on a winged horse… [then] that was a life worth living.
He adds that eliminating religious beliefs won’t solve all of our problems, obviously, but it will help society move closer to making more rational decisions on a larger scale.