Answer:
If the Argument from Revelation or Scripture is thought to be acceptable by some then there is the need to explain why one scripture is preferable to another and how the other scriptures that contradict the preferred scripture are to be disproved or disallowed.:
1. God must exist because the scriptures say so. (Bible, Koran, Vedas, Avestas, etc.)
2. The scriptures are true because they were written by God or by inspired individuals.
3. Who inspired these individuals? (God did)
It's a series of texts and groups of religions who have claimed there are sources made from God himself.