Bishop Spong heretic or healer?

Today I will be attending a lecture by the "controversial" Bishop Spong-retired. I'll post a review of his lecture soon. Currently I am reading his book "Why Christianity must change or die", a shocking title from a religious figure. I'll share my thoughts on this book and his other books in the future as well.

Bishop Spong has friends and enemies, a situation to be expected when discussing religion. Hopefully I will be able to determine if he is a heretic or a healer as has been said of him.