Given the foundational importance of circumcision in the OT and its prevalence in numerous debates in the NT, it is surprising that so little detailed work has been done on establishing a biblical theology of circumcision. This lack is even more surprising given that circumcision forms the background for some of the most hotly contested writings of the apostle Paul. The biblical material on circumcision seems to present vastly different and even apparently contradictory pictures of what circumcision means. The two key biblical concepts of righteousness and faith are closely linked to circumcision in debates carried on in Paul's letters and the early church. Karl Deenick shows that these two concepts are central to both the NT understanding and the developing OT understanding of circumcision. They are held together by the unfolding promise of a blameless 'seed of Abraham' through whose sacrifice the promised righteousness will finally come - a righteousness which will be enjoyed by those who trust in God's promise. Physical circumcision signified the goal of walking blamelessly before Yahweh, but it also represented the hope that Yahweh would provide a blameless seed through whom he would bring about that blamelessness in those who were not blameless/righteous. Circumcision of the heart is the appropriation of that promise by faith. It is the willing allegiance to Yahweh and the trust that Yahweh both forgives and makes righteous through the promised seed of Abraham.