Christian converts of the second century CE - writing a century or so after the death of Jesus - engaged in debates with non-Christians educated in classical Graeco-Roman culture, seeking to persuade them of the truth of Christianity. This book shows how they used the ancient Jewish Scriptures (what we call the Old Testament) in their arguments, even though their audiences were unfamiliar with those texts. The Scriptures are presented as a critically defining feature of Christianity, instrumental in shaping the way the new religion presented itself, as it strove to engage with and challenge the cultural and religious traditions of the Graeco-Roman world.