Gaffin on Union with Christ

At the same time, however, various considerations already adduced point to the conclusion that Paul does not view the justification of the sinner (the imputation of Christ’s righteousness) as an act having a discrete structure of its own. Rather, as with Christ’s resurrection, the act of being raised with Christ in its constitutive, transforming character is at the same time judicially declarative; that is, the act of being joined to Christ is conceived of imputatively. In this sense the enlivening action of resurrection (incorporation) is itself a forensically constitutive declaration. This does not at all mean that Paul qualifies the synthetic character of the justification of the ungodly. The justifying aspect of being raised with Christ does not rest on the believer’s subjective enlivening and transformation (also involved, to be sure, in the experience of being joined to Christ), but on the resurrection-approved righteousness of Christ which is his (and is thus reckoned his) by virtue of the vital union established. If anything, this outlook which makes justification exponential of existential union with the resurrected Christ serves to keep clear what preoccupation with the idea of imputation can easily obscure, namely, that the justification of the ungodly is not arbitrary but according to truth: it is synthetic with respect to the believer only because it is analytic with respect to Christ (as resurrected). Not justification by faith but union with the resurrected Christ by faith (of which union, to be sure, the justifying aspect stands out perhaps the most prominently) is the central motif of Paul’s applied soteriology.

Richard Gaffin
Resurrection and Redemption, p. 132