The Christian "doctrine of grace" has its core and origin in Paul's adaptation of the Greek term charis. It has long been recognised that Paul's usage of the term charis differs noticeably from the meaning it has in the rest of the Greek literature, including the Greek Old Testament.
Even if Paul was not the first to use the term in the Christian context, he was certainly the one who made it into an important concept of the early Christian theological language. The first part of the present study analyses the content of the concept in the authentic Pauline texts.
As a basis it takes the observation that Paul often uses charis as a contrasting notion, opposed to God's law: by charis he does not describe an attitude of God, but rather a way of communication, of God's dealing with people. This leads to further characterisation of Pauline charis as God's active power, which replaces "sin" as the central reality in control of human life (Paul uses the metaphor of kingly rule).
Further clarification of the concept is sought in examining its relationship to other concepts, linked to it either etymologically (the "gifts of grace" - charismata, the collection of money to support the church in Jerusalem, which Paul also calls charis, and greetings) or logically (Paul's pneumatology and a network of correlated terms). The second part of the study goes on to examine developments in the deutero-Pauline writings, where charis had already become an established part of soteriological statements in particular.
The third part abandons the mainly synchronic approach of the study and returns to the question of possible sources or inspirations for the Pauline concept. Although there is no direct terminological link, the most likely background is still the Old Testament.
As a possible source of the Pauline idea the study proposes the contrast statements, in which God stresses his new intervention not only over against the failings of his people, but also with respect to the whole previous history of Israel. Such statements typically appear in Deutero-Isaiah and the study points out especially the passage Isa 43:16-28, from which Paul quotes in 2Cor 5:17.