God made the only person who knew no sin to be sin for us

For He made Him who knew no sin to be sin for us, that we might become the righteousness of God in Him. 2 CORINTHIANS 5:21

The fifteen words in the original Greek in this verse express the doctrine of substitution like no other single verse in the Bible. God made the only person who knew no sin, the Lord Jesus Christ, to be sin for us. Some people mistakenly think this means that Jesus became a sinner—that, on the cross, He actually was punished because He was a sinner. The truth is that, on the cross, Jesus was as holy as He ever was in the eternity before or the eternity after. On the cross, God treated Jesus as if He had personally committed every sin ever committed by every person who would ever believe, though, in fact, He committed none of them. God put the punishment for our sins on the sinless Son. The rest of the verse says that “we might become the righteousness of God in Him.” That’s the other side of substitution. God treated Jesus as a sinner so that He could treat us as if we were righteous. He was not a sinner, and we’re not righteous. That’s substitution. He fulfilled all righteousness so that His sinless life could be credited to your account. Pretty amazing, isn’t it? On the cross, God treats Jesus as if He lived your life so that He can treat you as if you lived His life. That is the heart of the gospel.