Are cellphones and wikis good for faith? Author and Christian blogger Challies applies the discernment taught in his first book (The Discipline of Spiritual Discernment) to the subject of digital technology. He writes that technology is from God, but its merits and downfalls depend on how people use new devices—and how they allow those devices to use them. Though Challies is not the first author to warn about overuse, he takes a unique, comprehensive view of technology through the contexts of Christian theology, theory, and everyday experience. After offering a brief history of technology from the steam engine to the mobile phone, he examines six ways in which the latest digital media are affecting our behaviors (e.g., reducing accountability, changing our perception of truth). As we "approach a frontier," Challies cautions readers to consider potential behavioral changes before they are written into our history. While he does not draw definitive conclusions, the questions he poses will give readers necessary pause and help them to take a careful look at technology's place in their lives. (May)