“When Paul resolved to ‘preach nothing but Christ and Christ crucified,’ this is centrally what he meant: the cross as a symbol of the process of personal transformation at the heart of the Christian life.” – Marcus Borg, The Heart of Christianity
Earlier in the book, Borg has made clear that he believes substitutionary atonement is an incorrect understanding of the cross – that it was only invented in the 11th century. He also believes that there is no actual process of being ‘born again’ – that all people are always in a relationship with God.
It would appear, then, that the Apostle Paul was a traveling motivational speaker – urging people to be better versions of themselves. I have trouble believing that such a message would have set off the dynamic and rapid growth of early Christianity.