For such a brief read, Sider does a great job of highlighting the moral apathy of Christians [especially in the areas of divorce, compassion, fidelity, racism and physical abuse] and puts forth a call to counter-cultural living that rejects individualism and isolation and embraces community and accountability in order to model Jesus' intention for the church. Though published in 2005, Sider's reflections resonate with the church today.
You can read Sider's book in a day or two. But, his challenge will stick with you for a long time. I'd highly recommend this book.