The following post is an abridged version of one of the 100 reasons πίστις Χριστοῦ is an Objective Genitive included in my forthcoming book:
100 Reasons πίστις Χριστοῦ is an Objective Genitive
Reason No. 33: Galatians 3.22
In Galatians 3.22, Paul refers to ἐκ πίστεως Ἰησοῦ Χριστοῦ (”by faith[/fulness] in [/of] Jesus Christ”). He refers to this phrase in the context of his discussion of how the law had imprisoned all things under the power of sin.
Paul’s argument in Galatians 3.22 continues into chapter 5, and is explored in his intervening analogy concerning Abraham and his seed.
Morna Hooker argues that the passage demonstrates that the promise to Abraham came to the Gentiles by their incorporation into Christ, the faithful one (1989:327-331). Her argument is that believers are the descendants of Abraham (3.6-9), yet as Christ is the only seed of Abraham (3.15-16), and faith came in Christ who shared Abraham’s faith (3.22-25), the promise must therefore be given to those who have faith through participating in Christ’s faith (3.22).
But Dunn queries why, if this was really Paul’s argument, Paul did not bring it out more clearly, by explicitly stating that Christ believed as Abraham believed (1991: 738). Dunn has more regard to the context of Paul’s argument, the central concern of which is how non-Jews could be considered Abraham’s children by sharing Abraham’s faith. As argued in Reason No. 81, Gal 3.8 refers to the faith of believers, and this is so right through to Gal 3.14, where the promise of the Spirit is declared to be received through faith, recalling the believers’ receipt of the Spirit through “believing what [they] heard” in 3.2 & 5. In Gal 3.15ff, Paul introduces a further argument, from the premise that Christ is the sole seed of Abraham in whom the promise was fulfilled. And as a result of this argument, the faith that justifies in 3.6-9 is understood in 3.22 as faith in Jesus Christ. Dunn rightly concludes that Hooker has “merged the two strands of Paul’s argument [3.5-14 and 3.15-25], and her thesis arises from the resulting confusion” (191: 738).