What are atheistic human purposes?

Answer 1

Atheism is not a religion, so atheists have all sorts of ideas about what the best way for humans to spend their lives are. Most atheists belive in doing the same things everyone does - looking after your family and loved ones, working hard to succeed, and helping to make your society better - but they believe these things are important because they help other humans, not because a god commands them to do it.

Different atheists have different ideas on what the "purpose" of life is. Most would agree that human life just exists, like trees or the sky - it's what you choose to do with it that gives it purpose. Because there is no afterlife, it's important not to waste your life.

Answer 2

"WE ARE GOING TO DIE…. and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Sahara. Certainly those unborn ghosts include greater poets than Keats and scientists greater than Newton. We know this because the set of possible people allowed by our DNA massively outnumbers the set of actual people. And in these stupefying odds, is you and I in our ordinariness that are here. We privileged few won the lottery of birth against all odds. How dare we whine at our inevitable return to that prior state from which the vast majority have never stirred." - Richard Dawkins

Basically to stop bitchin' and live life to the fullest and help others do the same.

The entire purpose of life is having sex and not dying.