John Loftus seems to me raising the distinction between "silver bullet" arguments that in fact persuade everyone, and arguments which, even though they don't persuade everyone, ought to persaude everyone. I made this exact distinction in my book, when I was talking about strong rationalism. Now, clearly, no arguments about, say, belief in the existence of God are satisfying to everyone. There are atheists and theists on the highest levels of education. But the strong rationalist can maintain that while the case for belief (or unbelief) is not in fact convincing to everyone, it should be. The evidence is strong enough to convince everyone who is well informed and rational; if a well-informed person rejects the evidence, it is rejected because he suffers from some species of cognitive pathology—that is, from some kind of failure or inability to recognize the truth. Consider what many academics believe about astrology. Surely there are plenty of people who believe in astrology, but I at least am inclined to suppose that a careful study of astrological beliefs will show that it is not reasonable to accept these claims.
C. S. Lewis’s Dangerous Idea, p. 31.
Such an argument does not have to be convincing. With this in mind I think there are plenty of silver bullets. That you don't see them merely means you have resorted to faith to overcome it. Faith, by the way, is irrational.
Again, I think talking about faith in this way obfuscates the issue, especially if you are talking to someone who accepts C. S. Lewis's definition of faith.
"Faith is that art of hold on to things which your reason has once accepted, in spite of your changing moods. Unless you teach your moods where they get off, you can never be either a sound Christian or a sound atheist, but just a creature dithering to and for, with its beliefs really dependent on the weather or the sate of its digestion. Consequently one must train the habit of faith.”