goodness, how on earth did Noah 'defend himself' against the whole world? Moses hadn't even written the Penteteuch at that time!
how did Paul defend the gospel of Christ before he had even written his own letters?
we are blessed to have revelation today in written testimony -- but it is not for us to defend ourselves, but for our Deliverer, and He has equipped us for every good work by giving us of His Spirit.
no matter how accurate the testimony in text you have, you cannot comprehend it unless the Spirit of God reveal it to you. this is why the Lord sent Philip to the Ethiopian, so that it could be shown to him what he was reading.
God is my defender.
not myself.
not a book.
the Lord Himself.