If I've got to tell ya, I guess it's probably not worth the bother. I don't like the approach you mention, but at least they're trying to play with the home team.
Even most atheists recognize that Jesus Christ is the most significant person in history. They just quibble about the details. You don't see anyone running around claiming that Julius Caesar or Alexander the Great or Napoleon or George Washington never existed. These Jesus-deniers are wishful thinking loons on a major scale.