The part of the book that most concerned me was their understanding of the gospel. The authors claim the gospel isn't the answer of Jesus to the sin-problem of men and women. Rather, it's "[God's] love and acceptance and vision for every human being... God's love for his created humanity."
That description of the gospel too easily marginalizes the passion, crucifixion, and substitutionary death of Jesus. In fact, if the gospel is merely about God's love and acceptance of every human being, then why would Jesus have to die? They go on to claim that the gospel isn't just about God's love, it's about love in general - people adopting children, having block parties, and planting trees... "it's all Kingdom, and it's all good news."
While Christians are called to love others, that's not the gospel - that's an outworking of the gospel. The good news in the New Testament isn't a message about us, it's a message about Jesus. The authors go on to claim, we should look for ways to "Witness to this gospel by bringing tangible slices of heaven down to life on Earth, and continue to do this until those we're reaching out to acknowledge that our ways are `good news'."
The gospel is not a message about me. It's a message about Jesus, who is more than sufficient for a person has the same problem a non-Christian does. It's called sin, and Jesus provides an incredible answer to it - His life. His good news is about Him, not about me trying to be Him.