One thing I don’t recall hearing critics of religion ever saying, but which I think should be said, is that the effort by scientifically literate theists, including religious scientists, to render their religious views compatible with science often requires them to adopt views at least as empirically ridiculous as their religious views. (I will in due course also discuss examples of sympathisers of religion who are guilty of this too; some of them are not religious.)
Evolution provides an example. The problem with marrying evolution with Christianity goes deeper than why Genesis should be any less literal than the Gospels; why would a god keen to have beings able to worship Him exist use an undirected route to that end? Biologists such as Ken Miller, Francisco Ayala and Simon Conway Morris, all of them Christian, argue human intelligence is a product of convergent evolution, so was as inevitable as are eyes or wings, and that this is why a god could rely on such a method. But convergent evolution, by definition, can only account for things that have evolved repeatedly. Miller has asked “what evidence” there is for this; the evidence is the dictionary. Because ignoring this objection requires such Christians to literally contradict themselves, their view is the worst kind that can exist. What is more, since the definition of two views (in this case Christianity and evolution) being incompatible is one needing to embrace a contradiction if accepting them simultaneously, should this route Miller et al have taken be truly necessary Christianity and evolution are indeed incompatible.
Not all Christian biologists take this view; Francis Collins, for example, surely a greater scientist than any of Miller, Ayala or Morris, believes in a god who helped evolution over the difficult jumps. An example he cites is human morality; this is to him an irreducibly complex system, so in truth he is like any other creationist. But how altruism such as that in humans can evolve was answered decades ago. A comprehensive summary of the relevant research is found in The Selfish Gene. (To it we should add that, since humans’ recent ancestry involved the group, and even the species, being very small, relatedness even to strangers was high, leading to further altruism, and that the gene–meme interaction removes the upper bound on altruism the Price equation places in the gene–only case.) To say human morality is unevolvable is thus mathematically absurd in the light of what we now know of population genetics.
The same charge can be made against any use of group selection in hypotheses; again, The Selfish Gene explains why thoroughly. Amongst those scientists now looking into how religion evolved (complex and time–consuming, it must have a Darwinian origin), those who view religion in a positive light invariably explain it in exclusively genetic rather than memetic terms, and they also invariably need to assume group selection makes sense. An error of this sort is as outdated as using Lamarckian accounts of evolution.
I mentioned in a previous post that the argument for a god from “fine tuned” physics gets the science wrong. (I didn’t have space to explain why this is so, but recommended a book by Stenger as a first read on the subject.) How is this any better than the worst factual errors of the arguments of creationists? Indeed, isn’t it ultimately a creationist argument? Are religious beliefs in creation better when about the Big Bang than when about historically later events in Earth’s chemistry or ecology? And, like the morality “argument”, the “fine tuning” case is used by Collins, as well as some of religion’s sympathisers such as Paul Davies.