The presuppositional argument for the existence of god basically comes down to "I assume god is true and the bible is divinely inspired; the bible tells me god is true, therefore god is true." It's obvious circular reasoning and begs the question from the onset. Despite the obvious flaws it is still a widely used argument for the existence of god.
2: Begging the question.
3: This logic can be used to prove almost anything. I assume I am god. I didn't know that I was god before now. Therefore, I must have used my divine powers to hide my godliness from myself. This illustrates my divinity as only a god can be divine. Hence, I must be god.
4: Evidence indicates that the original assumption is wrong. You must ignore verifiable evidence to still hold the original assumption as being correct.
For the life of me, I really do not understand how any theist actually thinks this is a solid argument. For once, I would welcome the input of a theist. How can any of you actually believe this?