If there's another position that should be evident among new atheists, it's that we love science. We love it so much that we're even accused of scientism! One of the interesting contrasts between science and faith is that both claim to be means of "knowledge", yet only one of them has given us reliable information about the reality we inhabit that we've been able to use for all those advances in technology that have made our lives better and easier. The theologians, meanwhile, still haven't figured out how to deduce what God (assuming one exists) actually is. We atheists are right to point out that science is the preeminent epistemological methodology in the world. Actually, it's the only one, because the others (like faith) don't actually have a methodology by which we can discern between true and false information through objective, independent verification.
But theists are very closely tied to the emotional security blankets of their religions, so they work very hard to elevate faith to the same level of epistemic prestige as science. There are two major ways they do this:
1. Claim that science can't answer the Big Questions
Science, so they say, may be able to tell us a lot about the natural world. But it can't tell us why the world exists, how we ought to live our lives, how we ought to treat others, or what things we should most value.
To point, that's true: science can only tell us how the universe works, not why it exists. And unfortunately, it can't give us any reason why we should even care about existing at all. But I submit that religion doesn't actually answer these questions either. At best, religion just pushes the question back a step.
Let's say, for example, that you decide that the reason you should value life is because God created you, he loves you, and he has a purpose for you. Well, why should you value that? Why should you care about God's plans? Maybe you don't even really like the idea of a deity dictating your destiny, and you'd rather just figure things out for yourself. Or perhaps you decide that this life is important because it is the prelude to an eternal life. Well, why should you care about that? Theism hasn't actually answered anything; it's just arbitrarily dictated that 'meaning' should be derived from supernatural things instead of found here in our Earthly lives.
And let's say that this world exists because God decided it should, and you go to Heaven when you die. Why does that world exist? Why should anyone care about heaven? Heck, why does God exist? What's the point? Why shouldn't God just destroy himself?
At a certain point, we simply take certain things as axiomatic, such as our intrinsic valuing of our lives, or that we generally value well-being and try to avoid suffering unless we find it necessary for some greater aim that will increase well-being. Even supernatural beliefs ultimately succumb to the idea that we should believe in God because it's ultimately what will maximally increase our well-being – self-interest can never be removed from the equation. Theism can displace that axiom and land it on the supernatural, but it's only shifted the problem around – it still hasn't given us a better reason for why we ought to have self-interest.
2. Claim that science requires faith, too
Theists also try to claim that science is based on philosophical assumptions which cannot be proved. Take C.S. Lewis' old argument from reason:
One absolutely central inconsistency ruins [the popular scientific philosophy]. The whole picture professes to depend on inferences from observed facts. Unless inference is valid, the whole picture disappears... unless Reason is an absolute[,] all is in ruins. Yet those who ask me to believe this world picture also ask me to believe that Reason is simply the unforeseen and unintended by-product of mindless matter at one stage of its endless and aimless becoming. Here is flat contradiction. They ask me at the same moment to accept a conclusion and to discredit the only testimony on which that conclusion can be based."Here's a similar perspective from a theist blogger:
...despite its pretensions to rationality, science itself is based on a faith that the future will be like the past. The rational process of induction, the method of logic upon which all scientific generalization is based, involves the premise that the observations scientists make about the past can be extrapolated into the future. But this assumption, as David Hume famously pointed out in the 18th century, is based not on reason, since it can be established neither by induction nor deduction, but on custom and tradition--things that atheists like Coyne claim characterize religion, not science.In other words, the idea that the world is reliable, understandable, objective, etc., is all just something we have to take on faith. And since science is just another form of faith, theists are justified in having faith in supernatural things (like gods).
But the problem is this: that the world can be objectively comprehended, that our brains give us a (generally) reliable understanding of the world, that reality exists objectively and independently of us, etc., are not assumptions – they are observations. And science can do something extraordinarily powerful that faith cannot: can make falsifiable predictions about reality.
Now you could, as an exercise in intellectual masturbation, push this into the realm of metaphysical absurdity by suggesting that we have to make the assumption that we really are making those observations, that we really are experiencing this reality, etc. And that would be correct; I'm assuming that I'm really here, in front of my computer typing these words, and that my existence is not the manifestation of, say, a unicorn brain suspended in a jar made out of magic carrots. But that's the case with any reality. Again, imagine you were in Heaven. Wouldn't you still have to assume you were really there? How could you be absolutely certain that you weren't still alive on Earth, perhaps in a coma or a vegetative state and merely imagining Heaven?
It's true that scientists do make some assumptions. For example, scientists make the assumption that the laws of physics are the same throughout the observable universe. But this is a reasonable assumption, because no matter how far into space we've peered, the laws of physics do appear to be the same and we can find no logical reason to assume they shouldn't be. We also make lots of unconscious assumptions on a daily basis; when I sat down to write this, I didn't feel a need to check my chair to make sure it my body wouldn't pass through it. But that's because in my entire life, and with all the interactions with other humans I've had, I've never heard any good evidence that solid objects can pass through one another.
So theists try, and fail, to paint science and faith with the same brush. But Stephen Hawking said it best:
"There is a fundamental difference between religion, which is based on authority, [and] science, which is based on observation and reason. Science will win because it works."