http://www.fivedoves.com/letters/feb2014/lewisb217.htm


Years ago I heard Chuck Missler on the radio speaking about how the critics suggest more than one author for the Old Testament book of Isaiah. Sadly, he even admitted that it once troubled him to the point that he himself doubted its authenticity, (such is the life of an intellectual, I guess). That is until one day when he was reading in the gospels where Jesus quotes Isaiah twice. Once from the earlier part of the book and then from the later part and gloriously, Jesus prefaces his final quote by saying "This same Isaiah (Esaias) also said..."  Right there, Missler said it was settled for him because he already accepted the reality and authority of Jesus so if Jesus said it's the same person writing the entire book then that was good enough for him.

It follows then that these critics are not rejecting the prophet but also the Word of God Himself who endorses the prophet.