On the first one, I heard one Christian apologist say that Cane and Abel (then Seth) simply married a distant sister.
What the fuck is a "distant" sister? Distant cousin, sure. But how the hell could someone who's your sister — being from both Adam and Eve, since there was no one else — be distant?
Well, that one is mostly just spurious excuse-making. It isn't exactly a reasoned argument.
The thing about that one is that it was in an apologetics book, not spoken aloud in a fit of desperate mental-flailing. I want to say it was one of Ray Comfort's books, either 'You Can Lead an Atheist to Evidence, but You Can't Make Him Think' or 'God Doesn't Believe in Atheists'. Someone wrote it down, and it made it through editors (assuming that anyone actually edited his shit), and no one said, "Uhhhhhhh, Ray? This is fucking stupid. Cut it out of the book."
Of course, if his books were held to that standard, they would be 6 pages long, including the title page, table of contents, and author's bio. If you know Ray Comfort, you know that he's profoundly stupid and vapid, even for a Christian apologist.
I've never made a Christian into an atheist on the spot, of course. If you're expecting that, you're going to be disappointed every time. It usually takes at least a year for the arguments to soak in, and for the Christian to realize that there's no sane reason to believe any of this religion junk. It can take a good while after that for people to shake the emotional conditioning of their childhood brainwashing and become confident in their new (lack of) belief system.
If you mean changing a Christian's mind about a specific argument that he/she made, then yes. A lot of the spurious nonsense is so stupid that an incredulous face and one or two pointed questions can bring someone around.
"But what about this argument."
"But what about this one."
"But what about ..."
At least one of them is published by Wing-Nut Daily (http://www.wnd.com/), one of the most crazed, racist, conspiracy-nut, conservative e-magazines out there.
And yeah, there are many choice sections of material, calling atheism an intellectual embarrassment ... saying the most preposterous stuff about evolution (he and Kirk Cameron are the originators of the crock-o-duck) ... and being a grade-A moron and more than a bit of an asshole.
Steve Shives did a series covering two of Ray's books, if you want a sample: An Atheist Reads Ray Comfort.
Yeah, it's freaking painful, but at least with Steve processing that dreck and adding his own commentary, it becomes something more entertaining.