In the Year of St. Paul: New Views on Justification
A feature of the Protestant view of justification that needs teasing out is the assertion that Paul teaches the imputation of Christ's righteousness as the immediate grounds of justification.
G.E. Ladd states in A Theology of the New Testament that "Paul never expressly states that the righteousness of Christ is imputed to believers. The fact remains that no text in the Pauline corpus speaks of justification in these terms. Paul does not set forth imputed righteousness but incorporated righteousness, which is a shorthand way of saying that believers are justified by union with Christ... thus, believers are justified only for the reason that they share in a corporate solidarity with the justified Messiah, and what is true of Him is (also) true of God's people. In Paul's discussion of justification, it is the terminology of being 'in Christ' which dominates."
- Michael F. Bird, 'Incorporated Righteousness: A Response to Recent Evangelical Proposals on the Imputation of Christ's Righteousness in Justification,' JETS.