Modern evangelicalism is drinking deeply from the waters of postmodern and contemporary sensibilities. And depending on who you read, that is a good thing, or the one thing that will eventually destroy the movement. It is possible to understand the current postmodern culture well and address it through the lens of traditional Christian faith, or you can use the culture as a template for reimagining the Christian faith. Many in the emergent movement, and some in the seeker-sensitive movement are doing the latter, and it doesn't please John MacArthur.
The Jesus You Can't Ignore begins strong. In his introduction, MacArtuhr outlines the pressing reasons for writing the book. The more he encounters and reads the new evangelicals, the more he worries they are giving up on the central and defining components of the faith for irenic encounters with those who disagree deeply with Christian faith. His introduction to the book centers on the leading thinkers of the emergent movement and the recently published, Evangelical Manifesto. MacArthur argues that both strains of modern evangelicalism are soft on everything that matters and strong on ideas that are dangerous to the faith.
The rest of the book extends his thesis through the life of Christ. Jesus wasn't "nice" the way many construe niceness today. He confronted, even instigated arguments with, false teachers believing and teaching that false doctrine was dangerous to the human soul. Even when the encounters resulted in repentance and belief, Jesus was never less than straightforward about the truth of the Gospel (e.g. his encounter with Nicodemus). Where writers like McLaren and Campolo seek for dialogue with other faiths, glossing over the distinctives of the Christian faith, MacArthur argues that they could not be further from the example of Christ.
The strength of the book lies in MacArthur's overwhelming biblical evidence for his point. Chapter after chapter, he outlines and does the exegesis necessary to describe several scenes from Jesus' life and how he encountered false teaching. From the obvious encounters to the Sermon on the Mount, the book is loaded with biblical evidence. In fact, the evidence is so overwhelming, I think it puts to bed the soft-headed emergent idea that Jesus was first of all nice to others and never confronted them with the truth. If they want that idea to be taken seriously, they need to engage with the scenes portrayed and explained in this book.
The weakness of the book was that MacArthur didn't, to my taste, engage the emergent authors directly. Early on he quotes them a few times, but after the second chapter, they are non-existent. The premise of every chapter is aimed directly at refuting what he sets up early, but I think the book would have a greater impact if he kept up with the citations.
Overall, this is a great book directed at one of the defining issues in evangelical theology today: will postmodern philosophy define our theology as well as our culture? MacArthur's answer is basically, "God forbid!" and he backs it up well.