"Every word of God proves true; he is a shield to those who take refuge in him. Do not add to his words, or else he will rebuke you, and you will be found a liar."
I also would direct the reader to I Cor 4:6:
"I have applied all this to Apollos and myself for your benefit, brothers and sisters, so that you may learn through us the meaning of the saying, "Nothing beyond what is written," so that none of you will be puffed up in favor of one against another."
(Above quotations NRSV, apologies to Br. Brown. I Cor 4:6 is fairly mangled in the KJV so I can't fault him for not recognizing its applicability here, I suppose.)
If you come from a conservative Christian background of any sort, you can't come to an understanding of the things he is writing about without some changes taking place in you.
"MORE IS NOT BETTER - Consequences of adding to the Bible"