This is a collection of essays that examine how those perceived as others were differentiated, excluded and devalued in various early Christian sources, both inside and outside the New Testament canon. Early Christian polemic is set in its larger historical and cultural contexts in essays that deal with ancient literary images of religious prejudice, ancient polemical labeling, and portraits of Christians as others in non-Christian sources. Many essays adopt an inter-disciplinary approach and apply social psychological or sociological concepts to analyze how images of otherness constructed and solidified early Christian identities. In this way it is possible to explain the othering processes in foundational Christian documents which have had a lasting influence on Christian attitudes to outsiders and which still shape contemporary Christian identities.