Remember the atheist billboard about slavery?

Recently, one Catholic tried to look for a rebuttal showing that the Bible wasn’t really pro-slavery.
Not having any luck, the person wrote to Mark Shea of the National Catholic Register for advice.
Shea responded with the following… and it’s a doozy:
I think that atheists like your friend really need to break free of fundamentalist magical thinking and learn to read books written by and for grownups.
Wait, what?!
We’re the ones guilty of “magical thinking”?!
We’re the ones who need to read books by “grownups”?
The guy who believes Jesus inhabits crackers and wine suddenly turns in Jesus’ blood after a priest says “Abracadabra” thinks that those of us who look for truth through science and critical thinking are the “magical” ones?!
Wow.
That’s not even the worst thing he writes. Later in his response, Shea suggests that if atheists achieve “our goal” of eradicating Christianity, then slavery will return to the world:
… the New Atheists are stone blind to this in their deep ignorance and arrogance and so fail to realize that the first result of extirpating Christianity is the return of slavery: a practice which goes on unabated outside of all the spheres of the world untouched by the Christian tradition and soon to return to the West if the New Atheists succeed in suppressing the Christian tradition.
As if Christians are the sole force keeping slavery in check around the world…
(Don’t bother reading the comment thread there. The comments appear to be from another article written two years ago. Maybe the Register was afraid too many people would criticize this idiotic response so they tried to be sneaky about it.)
if you’re curious, you can see a thorough documentation of how slavery appears in the “Good Book” at Skeptics Annotated Bible.