Some assert that God "finished" reconciling the world to Himself 2,000 years ago, and that He justified all people at that time ("not imputing to them their sins"). Now, they say, He has entrusted the ministers of the Word with the task of announcing that God finished reconciling the world to Himself in the past, and in this way, they say, people become "individually" or "subjectively" reconciled to God. They claim that Paul is teaching two separate things in these verses: (1) that God finished reconciling the world (i.e., all people) to Himself at the cross, and (2) that by preaching this truth, ministers of the Word enable hearers to become "subjectively" reconciled as well.
But that this is not how 2 Corinthians 5 should be understood is made clear by Martin Chemnitz's treatment of it in the Examination of the Council of Trent. He ties the reconciling of the world to the means of grace, specifically to the Ministry of the Word. God was in Christ, reconciling the world to Himself through the preaching ministry of Christ. So also Christ is present in the authoritative preaching ministry of the apostles, still reconciling the world to Himself.
It is not as if God actually "completed" the reconciling of the world to Himself 2,000 years ago, and then gave the Apostles the ministry of telling the world that the reconciliation was completed. Instead, God even now continues His work of reconciling men to Himself through this ministry.
I sense that some who balk at this understanding do so, for one reason, because the thought of such an authoritative Office of the Holy Ministry is repulsive to them. They would rather see the Pastoral Office as simply announcing the fact that pardon has already been issued, so that the pastors are simply passing on information or communicating what was already true. They don't like the fact that God actually and personally works through the ministry of the Word to pardon sins and to effect reconciliation. But this is exactly what God says of the Office of the Holy Ministry, not that the apostles/pastors are to announce something that was already done in heaven long ago, but "whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven" (Matt. 18:18).