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You ask an essentially semantic question. If molecules could replicate, it's doubtful anyone would call them "alive," but as this process became more complex (damage repair, enzymes, metabolism, etc.) eventually, everyone would agree that it is alive. But it's not like there would be one single step where everyone would agree the step is non-living, and the one of the next higher complexity everyone agrees is living, thereby bringing about a sudden transition from one to the other. So it gets down to, how exactly do you define the word "living?" That's why I call it a semantic question.

For example, are viruses alive? I personally say no, but mine isn't the only opinion. (My reasons: Viruses have no metabolism, and can't replicate unless something else does which they subvert. We can eat dead things and still live and reproduce, but viruses can't propagate unless they infect a living cell.) Viruses are very much a gray area between living and dead, anyway. And the Bible is silent on viruses, so that particular doctrine is unilluminating.

It is far from being a semantic question. Life is almost impossible to define and I say almost because maybe somebody will come up with a definition for it someday. Crystalline molecules reproduce. Black pieces of paper convert one spectra of energy, visible light, to another spectra in the infrared reange. Catalysts convert one type of molecule to another and transfer information. Fire consumes complex carbon chains and oxygen, releases heat and light and excretes smoke, and if you've ever seen forest fire jump a break, you've seen it reproduce, too. You might say, "Eventually the fire goes out." Starved of fuel, you and I will also go out.

The difference is that I can make those things, predictably, given a set of rules provided by scientific observation. I can pile all the chemicals in all the right places in all the right proportions onto a hospital bed and I can't make you. Even if it looked like you, it would not be alive.

So it gets down to, how exactly do you define the word "living?" That's why I call it a semantic question.

Dave Barry said it best:

Life is anything that dies when you stomp on it.

Full Disclosure: I'd love to read a P.J. O'Rourke piece on the subject.

Cheers!

Viruses have no metabolism, and can't replicate unless something else does which they subvert.

The inability to replicate is common to all parasites. Even humans can't survive without nutrition provided by other living things.

The difficulty drawing a line between living and nonliving is to be expected in an evolutionary scenario.

We don't know the history of viruses. They may be a relatively recent development, arising after cellular life.