A top notch speech writer will get their point across in a way that even an idiot can understand. They will explain even the most complex issues in a way that even the most retarded person on the planet can understand without even thinking. They will make sure that their oponents cannot twist their words and leave no ambiguities.
Now imagine a novelist who had a writing style that meant it took years of studying their works before you knew what they were on about.
Someone like Dan Brown has these qualities, his arguments, plot line etc are easy to follow. Is his true for the bible? No. Why wouldn't skydaddyum have written the bible to be like the da vinci code? Think about it, Bart Ehrman asks how many people have read the bible and how many have read the da vinci code. if the bible was the word of a skydaddy the wouldnt reading it have you on the edge of your seat instead of the da vinci code?