You may be getting assumptions about your motives because it sounds like a trick question. Why would I have a goal in life as an atheist? It's an opinion on one topic, not the most important thing about me. I'd rather be a mostly rational believer than a mostly irrational atheist.
As an atheist, what's YOUR goal in life?
As an atheist, what's YOUR goal in life?
I'm not anti-Christian. I'm anti-stupid.