My beef with the Fundamentalists is that I don't agree with them on what constitutes a fundamental belief of the Faith. Mine are pretty easy - the ancient Creeds of the Church: The Apostles' Creed, the Nicene Creed, and the Athanasian Creed. Fundys, however, seem insistent on having "fundamentals" that aren't actually essential to the Faith, and in some cases aren't even true.
For instance, Fundamentalists insist on a literal reading of Genesis, and the belief in a young Earth. I don't believe that Genesis was ever meant to be understood literally, and the notion of a young Earth appears to me to fly in the face of observable data. Neither of those things seems to me to have diddly to do with faith in Jesus Christ.
While Fundamentalists insist on Genesis being literal, they're just as insistent the Scriptures involving the institution of the Eucharist must be taken symbolically, and absolutely reject the Real Presence. Thus it appears that they take an altogether dogmatic view of stuff that doesn't have any real soteriological significance, and dismiss with an airy wave of the hand matters that are of ultimate importance to Christians, the very Words of Christ Himself. They seem to have somehow gotten things back to front and wrong side out.
As for what atheists say about Christians, how could anyone possibly care less? These are folks who cling to a notion that, if taken to its logical conclusion, can support nothing but either solipsism or the complete abandonment of any kind of epistemology at all. On one path they're stranded at the Cartesian "Cogito" and incapable of moving away from it in any direction. On the other path, since all the universe is simply a product of the random interaction of particles and energies, then all "knowledge" goes out the window, all of it being equally meaningless.
The atheist gets to say, " I think, therefore I exist." and stop there, unable to escape the universe inside his own head, of he can say nothing at all, since his every word and thought is, with all else in the universe, a random phenomenon.
So there.