In this paper, I explore the traditional religious account of what can make a life meaningful, namely, the view that one's life acquires significance insofar as one fulfils a purpose God has assigned. Call this view ‘purpose theory’. In the literature, there are objections purporting to show that purpose theory entails the logical absurdities that God is not moral, omnipotent, or eternal. I show that there are versions of purpose theory which are not vulnerable to these reductio arguments. However, I then contend that there is a problem facing purpose theory which no version can avoid. I argue that the best reason for holding a God-centred theory of life's meaning logically precludes the possibility of purpose theory being the correct version of it. More specifically, I argue that if a relationship with God is necessary for one's life to acquire meaning, this must be because God would have properties such as atemporality and simplicity, perfections which are incompatible with purposiveness. I conclude that religious thinkers have good reason to develop other theories of the way God could confer meaning on our lives.