"In other words how can you prove the Bible is the word of God by pointing out scriptures that say it is the word of God, as you would be using the very thing in question to try and prove itself? "
The Holy Bible is a historical document that has archaelogical evidence that events in the Bible did happen. Therefore, we Christians who use the Bible as proof of God's Word are validated for using it. A better question would be "Why does an atheist use the bible to disprove it if they don't believe in it anyway". Most of the time they don't read what they are challenging and the debate seems tedious in trying to explain to them the fallacy of their argument. Getting back to the Bible as evidence of the Word of God, we know Jesus walked the earth. Fact. We know their was an Arc of the Covenant. Fact. We know the walls of Jericho came down b/c of faith. Fact. The Bible prophesied Jesus Christ's coming. Fact. So we use the Bible to prove it is God's Word by the promises God kept, and continues to keep, to us.