Using evidence from a 2010 survey of 32 European publics, this article argues that belief in God increases disapproval for synthetic biology through two different mechanisms, depending on the strength of the individual’s belief. Among weak believers, belief in God appears to be associated with the increased availability and accessibility of the idea that genetic manipulation interferes with nature. Strong believers, in contrast, appear to also engage in an explicitly theological evaluation of synthetic biology, with opposition to synthetic biology resulting from the perception that the creation of new types of organisms encroaches on a domain of activity (creation) that has traditionally been considered to be a divine prerogative. Overall, our findings suggest that value predispositions can influence public attitudes towards synthetic biology even when individuals engage in explicit deliberation about the technology in question.