The third quest for the historical Jesus has reached an impasse. But a fourth quest is underway--one that draws from a heretofore largely neglected source: John's Gospel. In this book, renowned New Testament scholar Craig Blomberg advances the idea that John is a viable and valuable source for studying the historical Jesus. The data from John should be integrated with that of the Synoptics, which will yield additional insights into Jesus's emphases and ministry. Blomberg begins by reviewing the first three quests, reassessing both their contributions and their shortcomings. He then discusses the emerging consensus regarding demonstrably historical portions of John, which are more numerous than usually assumed. Peeling back the layers, we discover in Jesus's ministry an emphasis on purity and purification. The Synoptics corroborate this discovery, specifically in Jesus's meals with sinners. Blomberg then explores the practical and contemporary applications of Jesus the purifier, including the contagious holiness that Jesus's followers can spread to others.