Bishop and Pauline scholar N. T. Wright is well-known for his rejection of the doctrine of the imputed righteousness of Christ. He argues that everything that one would receive through imputation, one receives through union with Christ. Union with Christ makes imputation a redundancy. While Wright does not specifically state it in these terms, his rejection of imputation seems to rely upon the older tendency pointed out above, to subsume the order of salvation (ordo salutis) to union with Christ. Wright, for example, argues that the Reformed understanding of the order of salvation, while perhaps reflective of the Reformed tradition, is not necessarily reflective of Paul's theology. Rich Lusk, a former Presbyterian Church in America (PCA) and current Confederation of Reformed Evangelical Churches (CREC) pastor, has a similar understanding of the relationship between justification and union with Christ.
Lusk also sees a conflicting tension between the legal and relational categories in traditional Reformed theology: "The covenant of works construction strikes at the filial nature of covenant sonship. Adam was God's son, not his employee." Given the supposed incompatibility of the legal and relational, it should be no surprise that Lusk allows the believer's union with Christ to swallow legal aspects of the believer's justification:
"This justification requires no transfer or imputation of anything. It does not force us to reify "righteousness" into something that can be shuffled around in heavenly accounting books. Rather because I am in the Righteous One and the Vindicated One, I am righteous and vindicated. My in-Christ-ness makes imputation redundant. I do not need the moral content of his life of righteousness transferred to me; what I need is a share in the forensic verdict passed over him at the resurrection. Union with Christ is therefore key."
Here Lusk argues that union with Christ makes legal elements of the believer's justification redundant and unnecessary, specifically that of the imputed active obedience of Christ....
... The Reformed tradition bases the doctrine of the imputed righteousness of Christ, even his active obedience, on such passages as Romans 5:12-21 (WCF 6.3, 11.1; cf. Heidelberg Catechism, Q/A 60). Why, for example, does Paul contrast the disobedience of Adam with the obedience of Christ? Paul writes, "For as by the one man's disobedience the many were made sinners, so by the one man's obedience the many will be made righteous" (Rom. 5:19). As John Murray explains, "The parallel to the imputation of Adam's sin is the imputation of Christ's righteousness. Or to use Paul's own terms, being 'constituted sinners' through the disobedience of Adam is parallel to being 'constituted righteous' through the obedience of Christ." Clearly, Romans 5:19 restates what Paul has stated in the previous verse: "Therefore, as one trespass led to condemnation for all, so one act of righteousness leads to justification and life for all" (Rom. 5:18).
There is no mistaking the parallel between Christ's obedience, which is righteousness, and the imputation of this righteousness to the believer. Commenting on the abiding significance of Genesis 15:6 and the imputation of righteousness, Paul writes: "That is why his faith was 'counted to him as righteousness.' But the words 'it was counted to him' were not written for his sake alone, but for ours also. It will be counted to us who believe in him who raised from the dead Jesus our Lord" (Rom. 4:22-24). Note here the English Standard Version translates the Greek word logizomai as "counted," which the King James Version translates as "imputed." Here Paul taps into the ancient stream of the special revelation of the Pentateuch, the first five books of the Bible, to argue for the imputed righteousness of Christ, and arguably also has other passages such as Isaiah 53 in mind when writing these things: "Out of the anguish of his soul he shall see and be satisfied; by his knowledge shall the righteous one, my servant, make many to be accounted righteous, and he shall bear their iniquities" (Isa. 53:11; cf. 2 Cor. 5:19-21).
We should also note, however, that in all of Paul's argumentation for his doctrine of justification and especially the imputed active obedience of Christ, he can write everything that we have surveyed, and at the same time also write without qualification or wincing: "There is therefore now no condemnation for those who are in Christ Jesus" (Rom. 8:1). If condemnation is the antonym for justification, then we can also reword Romans 8:1 to say, "There is therefore now justification for those who are in Christ Jesus" (emphasis added). In other words, a robust doctrine of justification that includes the imputed active and passive obedience of Christ is not antithetical to our union with Christ, nor is it superfluous. Rather, it is the legal aspect of our union with Christ. As A. A. Hodge explains, our union with Christ has a federal and representative character. Once again, what God has joined together, let man not separate. This brings us to one last element to consider, namely that justification is the ground of our sanctification...
...In terms of union with Christ and justification, Berkhof therefore explains that "justification is always a declaration of God, not on the basis of an existing condition, but on that of a gracious imputation-a declaration which is not in harmony with the existing condition of the sinner. The judicial ground for all the special grace which we receive lies in the fact that the righteousness of Christ is freely imputed to us." What we must realize, then, is that the ground of our redemption is the work of Christ; correlatively, we should also recognize that the ground of our sanctification is our justification. In other words, apart from the legal-forensic work of Christ, received by imputation through faith, there is no transformative work of the Holy Spirit. Or, using the title of John Murray's famous book, apart from redemption accomplished, there can be no redemption applied (see WCF 11.3; Larger Catechism, Q/A 70).The entire essay can be read at Modern Reformation.