While the existence of a God may imply that humans have a purpose, nonexistence need not mean that humans have no purpose.
I should have said that differently. I mean like no purpose as far as religion goes. There being an after-life kinda thing. We would, of course, have a purpose on earth.
Care to expand on that? I think it's flat wrong. But let me take a step back. Do you think purpose is inextricably linked with consciousness? If not, why not? Do you think consciousness is real? It's certainly not material. Is anything real that is not material? And purpose certainly cannot be defined in mechanical terms -- that's a closed loop. Bottom line is you said a mouthful, with certitude, in a very few words but I don't think it will fly (to mangle my metaphors).