I don't aim to benefit humanity through my lack of belief in a god or gods.
I don’t think I put that very well. I should have said, what differences a lack of belief in God would make in human lives.
I think a little story might help me here.
Four friends with different worldviews are meeting for lunch. Pam Anybody believes in God. She believes in the healing power of prayer. John Everybody believes in healing crystals and positive thinking. Joe Nobody doesn't believe any of that. He thinks that if you want to help, then you go and do it, because we are all we have. Lisa Somebody tells the group "Guys, I found out yesterday that I have cancer." Shocked, the table falls silent. Pam breaks the silence, "Hey, Lisa, you know I love you. I will pray for you. I'll even ask my church to pray on your behalf." "Yes," John concurs, "I have some homeopathic medicine for you at my house. I'll bring it tomorrow. You know I'll be sending good vibes into the universe." Joe thinks for a bit, then says "What do you need me to do, Lisa?" "I sure could use a ride back and forth to chemo, Joe." "You got it." he says without hesitation.
Somebody needs help. Anybody could have done it. Everybody wanted to do it. Nobody did.
When we recognize that there are probably no gods who respond to our pleas, that any action to alleviate suffering comes from other humans, then we can actually start to solve some of the problems that we, collectively, face. Too many people use prayer and "positive energy" instead of really helping others.
This is not even mentioning when some religious person claims to know the mind of God, and uses this as an excuse to exercise his or her own bigotry to deny the rights of others. Or when fundamentalists want to hold back scientific education and advancement because they are convinced that it disagrees with their holy book. Or when extremists attack and kill folks who simply believe something different.
Now, I am not saying that if someone gives up god belief, that they suddenly become a better person. Atheists a human beings with prejudices and biases just like everyone else. What I am saying is a rational consideration of human needs, a recognition of basic rights, and empathy for our fellow denizens of Earth does not require any belief if god, gods or goddesses, and we would all be better of for it.