How has Christianity, a faith based on the teachings of one text (the Bible), divided into so many denominations?

There are many different ways of interpreting any religious book, including the Bible. Also, people have different personal experiences that cause them to perceive their religion differently.

These web sites go into more detail about the history of Christianity. Be sure to read the section on the Protestant Reformation in the second site.

http://www.religioustolerance.org/chr_ch.htm

http://en.wikipedia.org/wiki/History_of_Christianity