Teachers often use analogy—the comparison of one thing to another—to lead students to that all-important “aha moment.” In Protestant Worship, author O. Wesley Allen Jr. uses the analogy of physics—with its concepts of the big bang, time, space, matter, energy, and chaos—to explain the actions, reactions, outpourings, and responses of a worship service. Instead of the high liturgical perspective in which many worship textbooks are written, Allen’s practical and immediately useful instruction provides a rich and deep foundation, helping both beginning and practicing worship leaders not only understand the fundamentals of Protestant worship more fully, but also become equipped to plan and lead worship well.