Groups on Facebook (and other online forums) often suffer from the invasion of "trolls," outsiders who voice provocative, often intensely combative, comments for the purpose of stirring up discussions and making the members angry. They are very much like ants at a picnic: pesky, annoying, and nearly impossible to get rid of.
In the case of atheist groups, these trolls are usually devoutly religious people, theists, who may be visiting the group for a variety of reasons: some are trying, in a positive sense, to win converts and save souls, while some are trying, in a more negative way, to poke holes in our beliefs, and they often do that in a contemptuous way, by ridiculing what they imagine our beliefs to be. Often their conception of what our beliefs consist of is wildly erroneous.
While the attacks by theists on the beliefs of atheists are wide-ranging (including making the claim that we have no beliefs at all, which is easily answered by giving examples of what we believe), there are two recurring themes: (1) theists say that we atheists believe the universe itself came out of nothing; (2) they say that we believe life came out of nothing.
I've already written a description of my own belief as to where the universe came from (see "So Where Did It All Come From Then?", chapter 9 in my online book, The Book of Daniel: Testimony of An Atheist), so I won't go over that here. I did not, in the book, cover the corresponding question of where life came from, so I'll do that here.
I do not, in any sense, believe life "came out of nothing," but I think the confusion on that count comes from theists assuming that I agree with them that life is something endowed with a spiritual mystique, a "special quality" that goes beyond the physical materials it is made from. Where, the theist wonders, could that special, magical quality have come from if not the power of God?
But I don't agree with them on that. That is the whole point.
Life certainly didn't "come out of nothing." The ingredients for it were all around, in the early years of Earth. Life is made primarily from the chemical elements carbon, oxygen, nitrogen, and hydrogen, which are four of the most abundant types of atoms available in the early-Earth environment. Hydrogen, in fact, is the most abundant element in the universe. (There are other elements involved in life besides those four, in smaller amounts, but again, these elements are all sitting around at the surface of the Earth.)
Now, it's true that you can't just put carbon, oxygen, nitrogen, and hydrogen in a jar, shake it, and somehow produce life.
Or can you?
Amino acids are made of those four elements. What are amino acids? They are the basic building blocks of life. There are twenty different amino acids that life on Earth uses to make proteins, and proteins in turn are responsible for all of the chemical processes that constitute "life." They make life happen.
In 1953, Stanley Miller, using (and in part ignoring) advice from Nobel laureate Harold Urey, performed an experiment. You can see it summarized here: Miller/Urey Experiment. (This is a truncated transcript from an article on the Duke University website that is no longer available.) Miller mixed together methane (a gas composed of carbon and hydrogen), ammonia (hydrogen and nitrogen), pure hydrogen gas, and water (hydrogen and oxygen), and kept them together in a bottle. Why those four materials? Because they were the believed to be the primary constituents of the Earth's atmosphere billions of years ago when life began. Then Miller ran a continuous electrical spark through the system, in a sense for the purpose of "shaking it up" -- the energy spark caused the elements of the gases to rearrange themselves into new combinations and configurations. Why did he add the spark? To simulate the constant lightning storms believed to have taken place in the early Earth environment (just as they do today: there are an estimated 1800 lightning storms in progress at this moment on Earth, as you read this). Miller then left the concoction of early-Earth gases under early-Earth conditions alone for a week: aside from providing the lightning, he did not do anything to it.
At the end of that week, Miller found that there was a large concentration of various different amino acids in the bottle. The amino acids were among the various rearrangements of the atoms of the gases, caused by the input of the energy of the electrical spark.
It is true (I am not going to try to hide anything) that scientists in 2015 are no longer sure Miller was correct about what Earth was like billions of years ago: "There has been a recent wave of skepticism concerning Miller's experiment because it is now believed that the early earth's atmosphere did not contain predominantly reductant molecules. Another objection is that this experiment required a tremendous amount of energy. While it is believed lightning storms were extremely common on the primitive Earth, they were not continuous as the Miller/Urey experiment portrayed. Thus it has been argued that while amino acids and other organic compounds may have been formed, they would not have been formed in the amounts which this experiment produced."
Read the end of that. No scientist is saying that the conditions now believed to have existed in early Earth couldn't have produced amino acids. They are only saying there wouldn't have been as much of them as Miller got. And there is new, more recent confirmation of the fact that amino acids are really not very hard to produce and can be found in some very unexpected places (this is all in that same article cited above): in 1969, a meteorite fell in Australia. Scientists doing an extremely detailed examination of what the meteorite was made of ran into an unexpected discovery: The meteorite contained, among other things, more than 90 different amino acids. And in case you are thinking "They just let the meteorite get contaminated with Earthly material somehow," that is clearly not the case: of those 90 amino acids, only 19 of them exist on Earth. Wherever you think those 19 might have come from, there is no alternative to saying the meteorite brought the other 71 with it. Amino acids don't only exist on Earth. They are pretty easy to make, and they are everywhere.
The study of the origins of life is continuing, and is continuing to give us new insights. Consider this article, "The Origins of Life", from March, 2015. The subheadline on the article reads: "A new experimental system demonstrates that precursors of ribonucleotides, amino acids, and lipids may have simultaneously arisen from the same prebiotic chemistry." (Let me translate that: just as amino acids are one of the necessities for life, ribonucleotides and lipids are also in that category. "Prebiotic" means "from the period on Earth before there was life," and the article is summarizing research that shows that the molecules that turned into all of these basic ingredients of life may have formed at the same time, all from the same prebiotic soup.)
Now let me address what I think are the most likely objections a theist will have to what I have been saying. If you, yourself, happen to be a theist, hold off on your objections and keep your mind open just a little longer, until I finish. The responses that I anticipate from theists are:
"None of this proves God didn't create life." My response to that is that I wasn't trying to prove that. I believe that no Supreme Creative Being exists, and all I am trying to do here is justify my maintaining that belief when faced with the existence of Life. I do not, personally, see a reason to insist God must have created Life, because I see alternative explanations. Those alternative explanations have acquired more weight as science learns more about the nature of Life, and about the conditions required for bringing Life into being from non-living materials that are available in the environment (as opposed to "out of nothing").
"But science isn't sure yet about those alternative explanations. There is a lot unknown, and a lot of scientists who disagree with each other even about the known parts." That is true, but unimportant. Theists believe that the fact that scientists have not completed their studies and found all the answers proves that science is inadequate for explaining the Mysteries. But that view is based on a misunderstanding theists have about science. Science is not a "source of answers," the way religion claims to be. It's not about giving answers to all questions. It is about trying to find answers to the questions. As such, it is a work in progress, and it always will be. Science isn't in the same category as religion, another "system of knowing." It is a mode of inquiry, and theists never quite seem to get a handle on that distinction.
"But my religion does give me assurance. It does answer the questions." My response: Fine, I'm happy for you, but also sad for you at the same time. When you, the theist, see some event or phenomenon that you don't understand, it is your habit to say, "God must have made that happen." To me, that is taking the lazy way out. Saying such a thing gives you an excuse not to think. Since thinking is something the human brain is very well-designed to do, choosing not to think is throwing away the marvelous ability you were born with. That is the part that makes me sad.
Okay, if you have objections other than those, you can go ahead and voice them now.