"I'm an atheist, but people need religion. What are you going to put in its place? How are you going to comfort the bereaved? How are you going to fill the need?" is an argument Richard Dawkins commonly gets. His response to this argument is detailed here: http://richarddawkins.net/article,318,Im-an-atheist-BUT---,Richard-Dawkins

Is religion helpful even if it were not true? Do people need it to stay moral or have purpose in their lives and should atheists be trying to convert people away from religion if it provides obvious benefits to a person's life?