Psalm 139 is one of the most famous and most quoted chapters of the whole Bible. Some indeed have even constructed an entire Christian ethic of the unborn child from its famous central verses. But what do we think David is trying to say in this beautiful and mysterious poem? What can it teach us about how we should view fetuses in the womb, and have some gone too far in trying to use this psalm as the lynchpin of the anti-abortion movement? And, as we approach Christmas, does it shed fresh light on the marvel and mystery of the incarnation too?