I don't know what Buddhist you asked, but that is really off... A Buddhist's goal in life is to reach personal enlightenment. It's not really altruistic or theistic... And the Christian church I grew up in said our purpose in life was to live by God's teachings and to bring as many people as we could to Christ.
Speaking for myself, not just as an atheist, I believe my purpose in life is to do what makes me happy. For me, that means being successful in my future career, reading as many books as I can, and trying every drug at least once.
