Even those who are largely comfortable with the natural evolution of life can sometimes have issues with abiogenesis - the natural origins of life itself. There's apparently a massive psychological hurdle that needs to be overcome, when faced with the prospect that not only did life evolve itself through the last four billion years, but that it bootstrapped itself up from dead minerals. Much of that difficulty probably arises from the starkly different ways that living and non-living systems appear to behave. Life forms wiggle and move and chase things, while crystals just sit there. Life forms are animate
in complex ways that non-living systems don't usually exhibit.
But then again, sometimes they do. Researchers at Argonne National Laboratory recently published footage
of some experiments carried out with clusters of nickel molecules in an oscillating magnetic field. The experiments had nothing directly to do with the origins of life, but nonetheless produced weirdly life-like behavior. In a tuned magnetic field, chains of nickel particles were observed zooming about like segmented snakes, displaying apparent behavior that eerily resembled hunting, chasing and feeding among single-celled microbes in pond water. There's no magic involved, nor are the nickel chains alive. They're displaying spontaneous self-assembly... a complex response to a few simple physical rules interacting with each other.
Living microbes are similar to those nickel clusters, in that microbes are themselves clusters of molecules that self-organize according to the laws of physics and chemistry and display emergent behavior. Such behavior can seem disturbing when exhibited by dead bits of metal, but only because we instinctively regard living and non-living systems as fundamentally different. They aren't... which makes things more interesting.