Not a captive, I understand that. I can't call the book useless and then say it's the Word of God. For the sake of clarity, I don't think the Bible is reliable or the word of God. An important book it is, as our civilization rests (or unrests) on it.
However, I didn't follow the circular reasoning you point out. Neither did Spinoza (or so I think). He found a statement in the Bible and analyzed its logical consequences. As in, "if I say there's no food in the fridge, then there can't be carrots in it". If the article I read is all right, Spinoza found that such statement leads to conclusions that, in his humble opinion, cannot be supported. I think Spinoza was right and I wanted to hear opinions on the matter.