We don't have inherent purpose or meaning in our lives; we must make it ourselves. If a child of a deeply religious family dies at the age of five, did he/she have meaning or purpose? If a baby dies of SIDS, did it have meaning or purpose? If the answer to either of those questions is yes, then what meaning or purpose could they have had that lends itself to there necessarily being a god?
We make the meaning and purpose in our lives by the way we live and by what we do for society.