Looking at Christianity from a somewhat sociological, somewhat metaphorical comparative technological point of view, Christianity is like a virus, much like a computer virus in its workings, the difference being that the medium in which Christianity functions is in people's minds.
For lack of creativity, this phenomenon will be called a mind virus, also known as a meme. (Yeah, you get it.) Basically it follows a very common virus pattern, it promises you something, in order for you to expose yourself to it. A modern example of this is a virus that fools men all of the time. It comes in the form of email, and is spoofed to look like it came from a friend. The subject says something along the lines of "Brittany Spears Naked". Because men look at this and think, "Hmm, I think it would be pretty cool to see good ol' Brittany naked... and if the wife ever finds out, I can say I opened the email by accident" they click on it, and then the computer is infected.
Christianity uses this same principle. A 'friend' comes up to you, and says something along the lines of, "You ever wonder what happens when you die?" Of course you've wondered that... so you say, "As a matter of fact I have..." and by doing this, you have exposed yourself to the virus. So they implant the idea in your head, that there is a supreme being, and that he is omniscient, and omnipotent. He created everything, and he is all good, etc. They tell you about the trinity, which is really hard to understand, by design. They tell you that living in this supreme being brings untold rewards, and best of all, just for believing this, you get to live forever in a place where everything is perfect.
They also tell you about evil. Evil is the devil, the 'slanderer of light'. If your 'anti-virus' mindware (common sense) hasn't stopped this nonsense yet, this is another technique to disable that common sense. When you get that twinge of doubt, that feeling that something isn't right here, they tell you that is the devil, it is evil, trying to turn you from the path of righteousness. One of the things that makes this mind virus so insipid, is the fact that it makes you have 'faith' which is believing in things without any evidence at all. If you are infected up to this point, then your anti-mind virus software, your common sense, is completely corrupted, and you are ready to spread the mind virus.
So you go out, and you infect your friends, all the while pretending to be something good, a decent citizen, a role model, a 'Christian'. So you go and pretend to be something good, like Brittany Spears naked, and you spread this mirus, thinking that you are saving people from an eternity in hell, chilling with the devil.
The other thing that makes this mind virus very insipid is the fact that it uses all of the infected members for a common purpose, a modern example being a DoS, or denial of service attack, made popular in 1999 and 2000, several computers are infected then applied to the purpose of attacking one host, such as a corporation's web page, or server. The resulting traffic makes the site/server go down, and it becomes unusable to the public.
While the mind virus of Christianity doesn't seem to be as threatening, it applies the affected people, to a few common purposes. It uses their resources such as time and money to further the organization of the mind virus, both in people and other resources, such as vehicles, buildings, land, and other ways to spread the mirus. Christianity could be compared to a DoS attack on reason itself.
There are many different sects of Christianity, the parallel being modern computer viri, there are several different strains, and often times they end up competing for resources, such as vulnerable computers. In this way the different denominations are very similar, they are basically the same thing, slightly different, and they end up competing for resources, such as vulnerable people.
Fortunately, savvy computer owners create 'rescue' boot disks, that can help combat a serious infection, when used properly. Unfortunately no such parallel exists for people infected with Christianity.
You can't put common sense on a floppy...