One of the most controversial issues surrounding synthetic biology, and genetic engineering in general, relates to the question of manipulating DNA, which at times is labeled as the fundamental element of what defines "life." If we define life in this way, then the manipulation of life's components can be seen as an act of "playing God" on the part of the scientists, and this argument has indeed been vocalized by the Vatican and other religious organizations. How far does this argument go and what does this argument do politically and practically for driving the path of synthetic biology research? Also, how can we think about the ways that synthetic biology might change our concepts of the fundamentals of life in more subtle ways?