Does Imputation make the Resurrection superfluous?

On a recent post I made about Calvinists denying the sufficiency of the Cross, a Calvinist named Miguel made the objection that if Active Obedience is considered to be "adding to" the sufficiency of the Cross, then logically the Resurrection should be considered as "adding to" the sufficiency of the Cross as well. In the course of responding to him, I explained how the Resurrection has no place in the Protestant understanding of Justification, while it has an integral part of the Catholic view of Justification. I decided to dedicate a short post to this subject, because it has just hit me as to how serious the ramifications of severing the connection between the Cross and Resurrection are on the issue of Justification. 

The problem can be summarized as follows: in the Protestant understanding of Justification, man has legal obligations that need to be fulfilled, and Jesus fulfills these legal obligations in place of all those who would believe in Him. The legal obligations Christ assumed are twofold: suffering the punishment the believer deserved and living a life of perfect obedience the believer should have lived. This is Imputation. As noted in the post I linked to above, forgiving the believer puts them in a legally-neutral position in the eyes of the law, just as Adam was in while residing in Eden. But without a legal record of perfect obedience, man cannot be declared righteous in Justification. This is why Christ also has to live a life of perfect obedience to be able to give the believer this 'positive' (as opposed to a 'neutral') standing before God. The problem here is that the Resurrection has no place in this Protestant understanding of Justification. Man can be justified regardless of whether Christ was Resurrected, since there is no 'forensic' component to the Resurrection so as to tie it into Justification. So how do Protestants (particularly Reformed) explain the Resurrection? Presbyterian theologian R.C. Sproul explains the role of the Resurrection in Justification as follows:

It is clear that in His atoning death Christ suffered on our behalf, or for us. Likewise, His resurrection is seen not only as a vindication of or surety of Himself, but as a surety of our justification. Here [Romans 4:25] justification does not refer to our vindication, but to the evidence that the atonement He made was accepted by the Father. By vindicating Christ in His resurrection, the Father declared His acceptance of Jesus’ work on our behalf. Our justification in this theological sense rests on the imputed righteousness of Christ, so the reality of that transaction is linked to Christ’s resurrection. Had Christ not been raised, we would have a mediator whose redeeming work in our behalf was not acceptable to God. However, Christ is risen indeed!

In other words, the only role the Resurrection plays in our Justification (according to Reformed theology) is that it acts as a 'receipt of payment', a sign that the Father accepted the Son's work. But this means the Resurrection plays no essential role in our Justification, only an accidental one. In fact, the Resurrection is not even necessary in that view, since God didn't need to give us a 'receipt' to still have accepted Christ's work. While it is true that Protestants would say the Resurrection plays an important role in other aspects of salvation, the fact is they must admit the Resurrection plays no role in Justification. But this cannot be. Justification is the central aspect of our salvation, and this Protestant view devalues the Resurrection and turns it into a mere historical event.

This troubling realization is made more pronounced when one considers the Scriptural testimony linking the Resurrection to our own justification in a very real sense. For example, Colossians 2:12 says, "having been buried with him in baptism, in which you were also raised with him through your faith," and Philippians 3:10, "I want to know Christ—yes, to know the power of his resurrection and participation in his sufferings," among other texts. Now Protestants would object by saying such texts are not speaking of Justification but Sanctification, since Protestants sharply separate the two. But not only does this admission affirm they're severing the Resurrection from Justification, they're also forced to mangle these very texts, since they appear right in the context of Justification. Indeed, the very text Sproul was referencing, Romans 4:25, makes the connection very clear: "He was delivered over to death for our sins and was raised to life for our justification." Recall that "was raised to life for our justification" is understood by Protestants to mean Jesus was Resurrected to prove God the Father had 'approved' and would thus gladly Justify us. But does this even make exegetical sense? I don't think so. St Paul is saying the Resurrection itself justifies us. And this makes sense when one stops and realizes the Resurrection corresponds to God giving new life to our souls that were formerly dead in sin. 

Clearly, Imputation is a direct attack upon the Resurrection, and thus is one more reason to reject it.