It will probably be hopeless to argue with such a nut. Turning around some of his comments, you might ask, "Do you believe in Heaven or Hell even though you haven't been there?" "Do you believe in God even though you haven't seen him?" "Scientists say if you walk off the roof of a tall building you will fall to the ground and probably be killed or maimed for life - do you consider that nonsense?" etc.
Here's a short letter to a newspaper I once posted:
"Creationists: On what day did God create the H1N1 virus? Did Noah take it on the ark, or did it survive on its own? How does this virus fit into the concept of Intelligent Design?"