What is Christian about Christian bioethics? The short answer to this question is that the Incarnation should shape the form and content of Christian bioethics. In explicating this answer it is argued that contemporary medicine is unwittingly embracing and implementing the transhumanist dream of transforming humans into posthumans. Contemporary medicine does not admit that there are any limits in principle to the extent to which it should intervene to improve the quality of human life. This largely inarticulate, yet ambitious, agenda is derived first in late modernity's failed, but nonetheless ongoing, attempt to transform necessity into goodness, and second the loss of any viable concept of eternity, thereby stripping temporal existence of any normative significance. In short, medicine has become the vanguard of a profane attempt to save humankind by extracting data from flesh. In response, it is contended that an alternative Christian bioethics must be shaped by the Incarnation, the Word made flesh. This assertion does not entitle Christians to oppose the posthuman trajectory of contemporary medicine on the basis of any natural or biological essentialism. Rather, it is an evangelical witness to the grace of Christ's redemption instead of the work of self-transformation. It is Christ alone who thereby makes the vulnerability and mortality of finitude a gift and blessing. Specifically, it is maintained that the chasm separating necessity and goodness cannot be filled but only bridged through the suffering entailed in Christ's cross, and through Christ's resurrection eternity becomes the standard against which the temporal lives of human creatures are properly formed and measured. Consequently, Christian bioethics should help us become conformed to Christ rather than enabling self-transformation.