Paul's use of "faith" language in Galatians

I just finished a rough draft of an excursus on Paul's use of "faith" language for inclusion in my Galatians commentary. My posts over the next few days will be bits and pieces of this excursus.

It perhaps borders on oversimplification to say that the essence of the Christian message and life can be reduced to the principle of faith, but that is not an unreasonable or indefensible position to take given the breadth and depth of that concept within the NT. The Christian life begins, continues, and ends with the individual’s response of faith to the creator God who has revealed himself definitively in Jesus Christ—his ministry, death, and resurrection. Faith encompasses the totality of humanity’s responsibility in salvation and entails much of what can be subsumed under other rubrics, such as discipleship, maturity, and sanctification. Although less debated in contemporary scholarship than the δικ- word group, the πιστ- word group is no less important for Paul’s argument in Galatians. The verb πιστεύω and the noun πίστις are used in very important passages, most notably the central theological statement of Paul’s argument in 2:15-21; as such the word group requires careful study. The purpose of this excursus is to examine Paul's use of the πιστ- word group in Galatians and describe how it fits within the message and argument of the book.