While some early Christian texts that are discussed in this volume, are classified as "gnostic", they are considered here as a witness of the views of educated Christians who stood in lively exchange with philosophical traditions. Ismo Dunderberg follows the approach that the philosophical schools of Ancient their followers should teach a way of life and examines questions about morality and lifestyle in non-canonical Gospels and in groups that were gradually denounced in the Church as heretical. It deals with the development of the soul from material concerns towards a run by reason of life, the mastery of one's own emotions, avoidance of luxury, the ideal "perfect man" as an instrument of moral instruction, assignments of people into different, on their moral Development stage based, Christian groups and debates regarding the significance of martyrdom. In addition, it provides a critical review of some recent research on the New Testament.