Lost Christianities: The Battles for Scripture and the Faiths We Never Knew

This historical study examines the diverse forms of Christianity that flourished in the first three centuries CE but ultimately disappeared as orthodox Christianity emerged victorious. Ehrman investigates various early Christian groups including Ebionites, Marcionites, Gnostics, and proto-orthodox Christians, analyzing their distinctive beliefs, sacred texts, and practices. The work demonstrates how radically different these movements were from one another, particularly in their conceptions of God, Christ, salvation, and the relationship between Judaism and Christianity.

Ehrman employs critical historical methodology, drawing on recently discovered texts like the Gospel of Thomas and the Gospel of Judas alongside patristic sources to reconstruct these lost traditions. He argues that early Christianity was characterized by remarkable theological diversity, with competing groups each claiming authentic apostolic authority. The Marcionites, for instance, posited two distinct gods—a wrathful creator deity of the Hebrew Bible and a loving father revealed by Jesus—while various Gnostic groups developed elaborate cosmologies featuring multiple divine beings. The Ebionites maintained that Jesus was fully human and that followers must observe Jewish law, directly contradicting emerging orthodox positions.

The work's central thesis concerns the contingent nature of orthodox victory. Ehrman contends that proto-orthodox Christianity prevailed not through divine providence but through superior organizational structure, strategic textual production, and effective polemical campaigns against rivals. He details how proto-orthodox leaders like Irenaeus systematically attacked alternative Christianities as heresies while establishing mechanisms for determining authentic scripture and doctrine. This process culminated in the formation of the New Testament canon and the suppression of competing sacred texts.

The study makes significant contributions to debates about religious authority and divine revelation. By demonstrating that core Christian doctrines about God emerged through historical conflict rather than unanimous apostolic witness, Ehrman challenges traditional accounts of Christianity's divine foundation. His work suggests that orthodox theology represents one historically successful interpretation among many rather than the inevitable unfolding of revealed truth. This historical relativism has implications for contemporary theological claims about God's nature and intentions. While Ehrman maintains scholarly neutrality regarding ultimate theological questions, his historical analysis undermines appeals to early Christian unanimity as evidence for orthodox truth claims. The work thus provides important historical context for evaluating competing claims about divine revelation and religious authority.