I am really surprised at all the people who are saying the original letter had to have been an intentional joke. Haven’t you looked at Ray Comfort/Kirk Cameron/Kent Hovind on YouTube? They say essentially the same things! For another example, I was sent this link (scroll down to where it says “What Are The Scientists Saying?”) to a 50 page document full of nonsense, garbled science and creationism, and random invalid arguments against evolution, all just as silly as this.
Some simply don’t understand Poe’s Law. It states that parodies of fundamentalism will be indistinguishable from the real thing. This letter is indistinguishable by any measure from any of the routine creationist lunacy you can find just about anywhere you look.