When one discusses the atonement, one objection is that it is unjust for someone who is unconnected to us to die in our place. Paul seems to anticipate that objection, and in chapter 6 he makes plain that it is no mere “legal fiction” that has taken place. Because what God declares to be the case actually is the case, we see that we can be considered to have both died with Christ and have been raised with Him. Thus, it becomes clear why faith is so vital, for it is in faith that we become united with Jesus, and the things He has done on our behalf become counted as though we ourselves had done them.
One of the greatest mysteries of the Bible is, of course, the precise mechanics of how this happened. Clearly on the one extreme we are not conscious of having experienced dying with Christ. We are, on the other hand, expected to be conscious — both now partially and in the future fully — that we have been raised with Him. Is Paul merely using metaphor here so that we can add “it is as if” or “it is like” to every clause? Personally I suspect not, and I am confident that the tone of this passage, whilst not answering all our questions, goes a long way towards explaining why it is entirely just for Jesus to have been punished on our behalf. There is also similar language in Romans 7 — and note the link Paul makes between Jesus’ resurrection and our empowerment to bear fruit for God.
“Do you not know that all of us who have been baptized into Christ Jesus were baptized into his death? We were buried therefore with him by baptism into death, in order that, just as Christ was raised from the dead by the glory of the Father, we too might walk in newness of life.
For if we have been united with him in a death like his, we shall certainly be united with him in a resurrection like his. We know that our old self was crucified with him in order that the body of sin might be brought to nothing, so that we would no longer be enslaved to sin.” (Romans 6:3-6)
“Likewise, my brothers, you also have died to the law through the body of Christ, so that you may belong to another, to him who has been raised from the dead, in order that we may bear fruit for God.” (Romans 7:4)
Continues with “The Atonement in Romans 8”