Reading some of the altercations between Jerry Coyne and Edward Feser has got me wondering: when do we need to delve deeply into the other side's arguments, and when is it OK (if ever) to give a simple answer and move on? Life is short, and I don't want to spend the rest of it reading a bunch of clap-trap just in order to debunk it. On the other hand, as True Skeptics™ we want a rational basis for what we believe - we don't want to dismiss some idea just because it interferes with our preconceived worldview. So we feel a certain obligation to look into the other side's arguments in detail. And if we fail to do our due diligence, people like Feser and William Lane Craig end up running circles around us.
So, here are some guidelines to help decide when enough is enough.
Know your audience; know your argument. It is, it seems to me, perfectly legitimate to address simple arguments for God with simple answers. Most believers don't believe because of some philosophically sophisticated argument of Aquinas or Craig. Rather, they are thinking something like, "Everything had to come from something." To this, it is enough to reply, "No, it didn't," or "Saying it came from God just pushes the problem back one step."
So it seems fine to write books or blogs that address the popular arguments for God while leaving out the philosophically sophisticated ones. If people like Feser complain about this, one need only point out that there are philosophically sophisticated answers already out there for those sophisticated arguments, and anyone who cares to do so can read up on them.
On the other hand, if you are addressing a particular argument for God, you had better understand the different versions of that argument, and the responses to them, and the responses to the responses, or you will end up with the taste of shoe leather in your mouth. It makes no sense to invent your own version of the Cosmological Argument and then proceed to knock that down - that's a classic straw man fallacy.
Triangulate. If prominent experts on the other side have abandoned a particular line of argument, it seems legitimate to ignore that line. If someone tries to argue that humans and dinosaurs lived at the same time because of the Paluxy footprints, I only need to point out that not even the Institute for Creation Research defends the Paluxy claim any more. Similarly, given the fact that theistic philosophers like Richard Swinburne and Alvin Plantinga have agreed that there are no valid deductive proofs of God's existence, I don't feel the need to pursue those any more. If Feser thinks he has rehabilitated Aquinas's cosmological proof and that all atheists need to read his book to find out how, well, fine: when he has convinced his fellow theists that he's done so, then I might look into it. Until then, I'm not going to waste my time.
Remember that the courtiers are sometimes right. PZ Myers has identified the "Courtier's Reply." In brief, the term refers to those who respond to the cry "The Emperor has no clothes!" with learned sneers, "He has apparently not read the detailed discourses of Count Roderigo of Seville on the exquisite and exotic leathers of the Emperor's boots..." and so forth.
But here's the thing: the courtiers are sometimes right. There are many highly educated and highly intelligent believers, and they have thought long and hard about their positions, and can defend them ably. When you run up against one of these, you should either shut your mouth or do the hard work of learning the real issues and responding to them. Giving a simplistic answer to a complex question is worse than giving none at all (see Know your audience above).
Atheists should respect the intelligence of their opponents. We think we have the better arguments. If we do, we should welcome the engagement with the best and the brightest among the theists.