Indeed, those of us who paid attention in class, learned that Wöhler killed off vitalism in 1828, when launching organic chemistry… There’s no difference between a hydrogen atom in a water molecule inside a human body, and a hydrogen atom in a water molecule in interstellar space.
For that matter, every molecule in our bodies is, when isolated, non-living. Extract glucose from a sample of your blood, and pop the resulting solid crystals in a petri dish, and there’s no obvious way of telling them apart from a sample of synthetic glucose. A sophisticated scientist might decide to check the ratio of 13C to 12 C and gain clues from that, but even that test would require very sensitive instruments to pick up any difference, and assumes that the materials used to make the synthetic glucose sample had a different isotopic ratio to begin with. If the starting materials had the same isotopic ratio, you wouldn’t be able to tell the difference.
For that matter, it would be possible to synthesise a molecule such as human insulin from scratch, and again, differentiating that synthetic insulin from insulin extracted from a blood sample would be difficult even for a fairly sophisticated chemist. Admittedly, such an exercise in total organic synthesis would be a formidable undertaking, but it’s certainly possible in principle.
EDIT: oh look, a total organic synthesis of human insulin has been reported in the organic chemistry literature … courtesy of this article in Journal of the American Chemical Society.
Of course, the boundary between “life” and “non-life” starts to look pretty blurred, when you observe, as Gerald F. Joyce has done, RNA strands not only self-replicating when in a solution of bare nucleotides, but undergoing Darwinian evolution whenever a chemical gradient exists.