From Counted Righteous in Christ (Piper, John. Wheaton: Crossway Books. 2002). Footnotes and bracketed material in other languages removed by me.
Death is not first, and most deeply, owing to our own individual sinning, but to our being connected with Adam in such a way that his sin really made us guilty and liable to condemnation. (100-1)
The judicial consequences of Christ’s righteousness are experienced by all his people not on the basis of their doing righteous deeds like he did, but on the basis of their being in him and his righteousness being imputed to them. (101-2)
So the problem with the human race is not most deeply that everybody does various kinds of sins. Those sins are real, they are huge, they are enough to condemn us, and they do indeed play a role in our condemnation. But the deepest problem is that behind all our depravity and all our guilt and all our sinning there is a deep mysterious connection with Adam, whose sin became our sin and whose judgment became our judgment. And the Savior from this condition and this damage is a Savior who stands in Adam’s place as a kind of second Adam (or “the last Adam,” 1 Corinthians 15:45). By his obedience he undoes what Adam did. By his obedience he fulfilled what Adam failed to do. In Adam all men were appointed “sinners,” but all who are in Christ are appointed “righteous” (5:19). In Adam all received condemnation; in Christ all receive justification (5:18). (102-3)