Christianity is the world’s largest religion, but it is far from unified. Its denominations number in the tens of thousands, and each has its own recipe of doctrines, practices, and governance. Christianity’s splintered condition is not a benign form of diversity. Rather, believers are divided into denominational camps and have limited understanding of others’ beliefs. All too often, these divisions have fostered mistrust, intolerance, persecution, and even war. This denominationally neutral book is intended to foster understanding by challenging all Christians to explore outside the figurative walls of their respective denominational fortress. The history of Christian splintering is the origin story of Christianity’s denominations and is therefore a starting point in an effort to understand fellow Christians. A journey through the history of the religion’s splintering, messy as it is, is not without risk. Thoughtful explorers will grapple with tough questions relative to Christian truth and denominational certainty. If in the end, the intrepid explorer finds renewed faith, a broader and more mature perspective, a more receptive heart and mind, and a clearer view of fellow Christians, then the journey will be well worth the effort.