What did Paul mean when he said, "he became sin" for us (2 Corinthians 5:21)? For it is written, "Cursed is everyone who hangs on a tree!" (Deuteronomy 21:23; Galatians 3:13).
Paul states in II Corinthians 5:21
υπερ ημων αμαρτιαν εποιησεν .
I am quoting the TR (Stephens 1550) but the words are undisputed in any variance that I know of.
The EGNT (Englishman's Greek New Testament) translates this as
for us sin he made
Young's Literal Bible conveys the alternative meaning of υπερ :
on our behalf He did make sin
εποιησεν is an inflection of the word ποιεο, poieo, [Strong 4160], which means 'make' or 'do' The KJV translates it 'make' 353 times and 'do' 102 times. It also uses a smattering of other words, 'execute' 'bring forth' 'provide', and others, about 100 times. [Numbers are from Young's Analytical Concordance.]
To translate εποιησεν as 'become' is unsupported by any Lexicon on my bookshelf (BDB, Thayer, Liddell & Scott, Strong) and unsupported by the following English translations :- Young, EGNT, KJV, J N Darby, William Tyndale and The Wycliffe; all of whom have 'made' or 'did make'.
The verb εποιησεν also occurs in the phrase written by John in John 4:46
οπου εποιησεν το υδορ οινον [TR, Stephens 1550]
'Where he made the water wine' [EGNT, KJV]
So water had something(s) added and it became wine. There was that which, added and suffused throughout the whole body of water, changed it into wine.
It was still a body of liquid, and was still a body of (mostly) water. It had not 'become' something else entirely. But that which was now added to it made it wine.
Something was there that had not previously been there. And it was there in every part of the whole body of it. Not any part of it was unaffected.
It was made wine - by the addition.
God, sending his own Son in the likeness of sinful flesh, and about sin (the word is περι) - condemned sin in the flesh. Romans 8:3
Sin was condemned in the flesh of Jesus Christ.
Once he was dead, sin was gone.
This is a truly momentous subject, having ramifications throughout the Hebrew scriptures : for example the word kaphar - translated 'atonement' - which actually conveys the concept of 'containment' (see kaph, the hand).
And the subject is a thread that runs through every one of the twenty seven books of the Greek scriptures.
One dislikes to be so brief on such a subject, but needs must.
Ambrose cited exactly the same Scripture in his explanation of 2 Corinthians 5:21:
The Lord is also called an accursed thing, not because the Lord was turned into an accursed thing but because he himself took on our curse. He says: For he is accursed that hangs on a tree. ... It is written that he was made sin, that is, not by the nature and operation of sin …; but that he might crucify our sin in his flesh, he assumed for us the burden of the infirmities of a body already guilty of carnal sin.*
Also, in many places in the Old Testament the sin offering could itself be called a "sin". For example, the JPS Tanakh translation of Exodus 29:14 reads:
The rest of the flesh of the bull, its hide, and its dung shall be put to the fire outside the camp; it is a sin offering.
but the Hebrew underlying sin offering is the single word חַטָּאת, which can mean both "sin" and "sin offering". The Greek Septuagint translation of the Hebrew usually translates חַטָּאת everywhere with the single word for "sin", ἁμαρτία. Perhaps Paul, writing in Greek, had the Septuagint in mind when he phrased the verse as he did.
* The Sacrament of the Incarnation of Our Lord, VI.60