What does atheism have that Christianity doesn't?
While waiting for them to answer - there would seem to be crickets there - I'll give you a few observations.
You would think that these atheists who are trying to convert Christians to their religion would want to be able to tell them what they'd get from atheism that Christianity doesn't provide them. In the context of this particular blog brawl, the question might be put as what they'd get from converting to atheism over retaining their liberal Christianity. I don't see that there's a single thing in it for all but a very few academics and those who want to live their lives of nihilistic, amoral depravity at the expense of the large majority of living beings.
Atheists can't offer them hopes for justice or equality because atheism doesn't contain even the acknowledgement that those are real endowments that people have a right to. Atheism doesn't even contain the idea that human rights or the rights of any living beings are real and more than a mere delusion. When you press a sciency atheist-materialist on that question it's far more likely that they will, in an effort to preserve their materialism, they will deny those are there. And it's not just the current fashion of evolutionary psychology and other sects and cults of Darwinism. It's not any accident that the previous majority faith in such things, behaviorist psychology produced popular lit about a scientific world "Beyond Freedom and Dignity"* where we will be scientifically managed into a superficial and banal contentment like a well managed herd of well provided for sheep. And, of course, when pressed to the ultimate they go a hell of a lot farther than that denying that even the very consciousness which comprises our real being exists.
Though in all of their tortured, twisted, turgid verbiage over that, one thing that inexplicably is, apparently, to survive is the notion of academic-intellectual distinction for such ideas and the inexplicably to be honored right to propriety over them and the professional, academic, legal and monetary rewards they are, somehow, entitled to as well as justice against those who deprive them of, especially, the proprietary and monetary rewards of such ownership. They never seem to question the existence of the owners of such mental property as they are in the business of producing.
So, there is something in it for the scribbling, publishing, teaching entirely inconsistent and entirely unwilling to live with the consequences of their ideology atheist, though, if made a matter of law and custom, there's not even the ownership of the vast majority of us to even own our own consciouness, never mind a right to equal justice and the liberality that an honest application of The Law, the Prophets and the Gospel say is our due as a matter of endowment by God.
Naw. atheism has got nothing that is of any use to people who don't want to live as conceited, arrogant, snobs. As I've been saying, it destroys the very basis of egalitarian democracy. That is something that has been being asserted by materialists since at least the 18th century.
* Younger folks might never have heard of it but it was as big in the early 1970s as sociobiology and evo-psy would start being a few years later after the New York Times ordered everyone to read it.