Focus on Chapt 1, where Borg sets out a few of the major conflicts which have resulted in divisions that have shaped Christianity ie the adoption of Christianity by the Roman Empire – Jesus is Lord not the Emperor & the Nicene Creed (what you need to believe) (325 & 451), the Eastern Orthodox – Roman Catholic split (1054) resulting in Crusader conflict/slaughter in 1204, the Reformation where the Bible and reason replaced the authority of the Pope.
Borg identifies 5 approaches to Christianity in 21st century America – Conservative, Conventional, Uncertain, Former, Progressive. These categorisations resulted in much discussion: is it natural to expect a progression from one to another; how to encourage Conservatives and Conventional to see a wider vision than a narrow Biblical interpretation; what are the dangers for the church if it is dominated by Conservatives and Conventionals eg an attempt to wind back the past, become increasingly out of touch with society; is is possible to have worship together that satisfies most people in most categories.
Perhaps a focus on what Christians can and should do to assist society by showing the same love as Jesus did is more significant than ‘labels’.