Recent contributions in the study of Ancient Judaism and Greek Religion have shown in detail that the notion of the defiling force of moral failure was of preeminent importance for the moral and ritual thought, but also the soteriology of religions in Antiquity. Studies e.g. by Jonathan Klawans or Ivana and Andrej Petrovic help us to develop a grid of understanding of the relevant material which goes well beyond the unsatisfying distinction between a verbal and a spiritual understanding of the language of sin and defilement. What lacks in present scholarship is a thorough investigation of the issue in the texts of emerging Christianity in the first and second century CE. Among them, Hebrews is perhaps the single most outstanding example of a fusion of moral and ritual language and notions in soteriological perspective. The paper tries to situate and to profile the thought world of Hebrews within the wider context of Second Temple Judaism: In which way does Hebrews take up the notion of the "defiling force of sin"? What is the ontological status of defilement the text presupposes? In which way is Hebrew on common Jewish ground? What is the specific contribution of Hebrews to the discourse in 1st century Judaism and beyond?