For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him.
For. So C. Omitted in 'Aleph (') B Delta G f g, Vulgate. The grand reason why they should be reconciled to God-namely, the great atonement in Christ provided by God-is stated without "for" as being part of the message of reconciliation (2 Corinthians 5:19).
He - God.
Sin - not a sin offering [Hebrew, 'aashaam (H817)], which would destroy the antithesis to "righteousness," and would make "sin" be used in different senses in the same sentence; not a sinful person, which would be untrue, and would require in the antithesis "righteous men," not "righteousness;" but "sin" - i:e., the representative guilt-bearer of the aggregate sin of all men past, present, and future. The sin of the world is one; therefore the singular, not the plural, is used; its manifestations are manifold (John 1:29: cf. Romans 8:3-4; Galatians 3:13).
For us - Greek, 'in our behalf' (cf. John 3:14). Christ was represented by the brazen serpent, the form, but not of the substance, of the old serpent. At his death on the cross the sin-bearing for us was consummated.
Knew no sin - by personal experience (John 8:46; Hebrews 7:26; 1 John 3:5) (Alford).
Might be made. Not the same Greek as the previous "made." Rather, 'may become.'
The righteousness of God. Not merely righteous, but righteousness itself; not merely righteousness, but the righteousness of God, because Christ is God, and what He is we are (1 John 4:17), and He is "made of God unto us righteousness." As our sin is made over to Him, so His righteousness to us (in His having fulfilled all the righteousness of the law for us all, as our representative) (Jeremiah 23:6; 1 Corinthians 1:30); so that God 'imputes not our trespasses to us' (2 Corinthians 5:19). The innocent was punished voluntarily as if guilty, that the guilty might be gratuitously rewarded as if innocent (1 Peter 2:22-24). 'Such are we in the sight of God the Father, as is the very Son of God himself' (Hooker).
In him - in union with Him by faith.