Argument from scripture
The argument from scripture, at least as used by Richard Dawkins in The God Delusion, is essentially the argument that "I believe in God because the Bible says that God exists." This argument translates easily to other holy scriptures.
In order for this argument to be sound, one must demonstrate that the Bible (or other scripture of choice) is reliable. That is, one must show that if the Bible says something, then that statement is likely to be true.
However, the Bible has been shown not to be a reliable source of information. Geological evidence shows no trace of Noah's flood, and that the humanity (to say nothing of the earth) is far older than the 6000-10000 years predicted by adding up the ages of people in Biblical genealogies Astronomical evidence shows that the sun does not revolve around the Earth, and that the Earth is not flat. Contradictions between the four gospels (and other Bible books) casts doubt on their reliability.