I've looked over the site (I haven't read all of the articles, but I have read the main pages, main arguments, and a few of the articles), and I have to say that I do not buy what this guy is saying. I can't go into each of his articles in detail, because that would take a whole book, but I can point out some of the erroneous statements and reasoning that he (doesn't give his name, for some reason) uses.
The most blatant is his statement that the Christian church is the "worst terrorist organization in the history of the world." Anyone with a knowlege of history would know that such a statment is blatantly false. The author of the site goes on to accuse pastors of greed and thought control. While this may be true in some cases, it is by no means true in all, or even many. Most pastors in my experience has been devoted to serving God, but in order to do that, they have to have money to feed their families.
The whole thing reminds me a lot of the doctrines of the Jehovah's witnesses, who also claim that Jesus was the messiah, but not God. He uses a lot of the same arguments (in addition to a few wild ones that are his own). If you are going to view that site, and you do not have much experience the bible or answering cultists, then I suggest you consult this site for balance:
http://www.carm.org/witnesses.htm
There are also some relevant articles on the nature of the trinity and the other arguments against the deity of Christ on the page about Islam:
http://www.carm.org/islam.htm
You can also find helpful stuff from the main page:
http://www.carm.org
I have to go eat lunch now, but when I get back, I will go into this in more depth. In the meantime, consult the links that I have given in addition the the previously referenced site, and decide for yourself which one is more reasonable.