If you wanted to find one verse that encapsulates the glorious truth of the gospel, you couldn’t do much better than the words of the apostle Paul in 2 Corinthians 5:21. Describing God’s reconciling work Paul writes, “He made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him.”
That verse gets to the heart of the good news of the gospel—Christ’s substitutionary death on our behalf. And it gives us the confidence that Christ’s righteousness will be imputed to us. It depicts the blessed reality of both those great doctrines—that when God looked at Christ on the cross, He saw us; and when He looks at us now, He sees His Son. Can you imagine a greater promise or a richer blessing?
And yet, buried in that verse is a short phrase that often trips up Bible students. Worse, this phrase has become a playground for heretics and charlatans. By manipulating these few simple words, they pervert the character and nature of Christ, and pollute the gospel.
Here’s the phrase, in its context: “He made Him who knew no sin to be sin on our behalf, so that we might become the righteousness of God in Him.”
Those three little words seem innocuous. But in the hands of a man like Kenneth Copeland, they can unleash a world of blasphemous error. Copeland is effectively the leader and the face of the Word-Faith movement, which is the primary proponent of the prosperity gospel. Copeland was the chief disciple of Kenneth Hagin, and has expanded Hagin’s family tree of heresy through his mentoring relationships with Benny Hinn, Joseph Prince, and many others.
Copeland and many of his acolytes teach that the short phrase “to be sin” in 2 Corinthians 5:21 indicates that Christ actually became sinful on the cross. They say it wasn’t merely the penalty for our sins that He took on Himself, but all the sins themselves, exchanging His divine and righteous nature for the nature of Satan.
Here is Copeland in his own words:
The righteousness of God was made to be sin. He accepted the sin nature of Satan in His own spirit, and at the moment He did so, He cried, “My God, My God, why hast Thou forsaken Me?”
You don’t know what happened at the cross! Why do you think Moses, upon the instruction of God, raised a serpent upon that pole instead of a lamb? That used to bug me! I said, “Why in the world do You have to put that snake up there, the sign of Satan? Why don’t you put a lamb on the pole?”
The Lord said, “Because it was the sign of Satan that was hanging on the cross! I accepted in My own spirit spiritual death, and the light was turned off . . . made to be sin.”  Kenneth Copeland, “What Happened from the Cross to the Throne, Part 2” March 31, 2015.
Benny Hinn holds to the same erroneous doctrine. Hinn has declared that Jesus “did not take my sin; He became my sin. . . . He became one with the nature of Satan.”  Benny Hinn, quoted in Hank Hanegraaff, Christianity in Crisis (Eugene, OR: Harvest House Publishers, 1993), 155-156. Hinn embellished the point further one night on TBN:
He [Jesus] who is righteous by choice said, “The only way I can stop sin is by me becoming it. I can’t just stop it by letting it touch me; I and it must become one.” Hear this! He who is the nature of God became the nature of Satan when he became sin!  Benny Hinn, Trinity Broadcasting Network, December 1, 1990.
Even Joel Osteen—who reigns in his Word-Faith proclivities just enough to maintain his mainstream popularity—teaches this spurious doctrine:
Not only did Jesus pay for the punishment for your sins, the Bible says He actually became sin. He took sin upon Himself and into His being so that you could take God’s righteousness upon yourself and into your being. It’s the great exchange.  Joel Osteen, “The Great Exchange,” December 19, 2013.
Over and over these charlatans corrupt the nature of Christ and poison the gospel with these repulsive lies. Make no mistake—these are not small or insignificant errors. Accusing the Son of God of becoming a sinner is a direct assault on His divinity. Moreover, it’s an attack on the very aspect of His nature that made Him a suitable sacrifice for our sins in the first place: His righteousness.
In the Old Testament, the Lord specifically demanded a spotless, unblemished lamb as the sacrifice for sin (Exodus 12:5). Those sacrifices pointed ahead to Christ, who would serve as the one, true sacrifice for our sins. But His sacrifice would be worthless if He became sinful during His crucifixion. Not only would He have ceased to be a fitting sacrifice, He would have completely ceased to be God.
In his commentary on 2 Corinthians, John MacArthur explains that all of God’s Word testifies to the crucial truth of Christ’s sinlessness.
The impeccability (sinlessness) of Jesus Christ is universally affirmed in Scripture, by believers and unbelievers alike. In John 8:46 Jesus challenged His Jewish opponents, “Which one of you convicts Me of sin?” Before sentencing Him to death, Pilate repeatedly affirmed His innocence, declaring, “I find no guilt in this man” (Luke 23:4; cf. vv. 14, 22). The repentant thief on the cross said of Jesus, “This man has done nothing wrong” (Luke 23:41). Even the hardened, callous Roman centurion in charge of the execution detail admitted, “Certainly this man was innocent” (Luke 23:47).
The apostles, those who most closely observed Jesus’ life during His earthly ministry, also testified to His sinlessness. Peter publicly proclaimed Him to be the “Holy and Righteous One” (Acts 3:14). In his first epistle he declared Jesus to be “unblemished and spotless” (1 Peter 1:19); one “who committed no sin” (2:22); and “just” (3:18). John also testified to His sinlessness, writing, “in Him there is no sin” (1 John 3:5). The inspired writer of Hebrews notes that “we do not have a high priest who cannot sympathize with our weaknesses, but One who has been tempted in all things as we are, yet without sin” (Heb. 4:15), because He is “holy, innocent, undefiled, separated from sinners and exalted above the heavens” (7:26).  John MacArthur, The MacArthur New Testament Commentary: 2 Corinthians (Chicago: Moody Publishers, 2003), 214.
John goes on to explain that the most powerful testament to the sinless nature of Christ comes in His unbroken fellowship with the Father, summed up in the simple statement, “I and the Father are one” (John 10:30). John writes,
It is equally unthinkable that God, whose “eyes are too pure to approve evil” (Habakkuk 1:13; cf. James 1:13), would make anyone a sinner, let alone His own Holy Son. He was the unblemished Lamb while on the cross, personally guilty of no evil.  The MacArthur New Testament Commentary: 2 Corinthians, 215.
So how should we understand the idea that God made Christ “to be sin on our behalf”? Isaiah’s prophetic words give us the answer:
Surely our griefs He Himself bore, And our sorrows He carried; Yet we ourselves esteemed Him stricken, Smitten of God, and afflicted. But He was pierced through for our transgressions, He was crushed for our iniquities; The chastening for our well-being fell upon Him, And by His scourging we are healed. All of us like sheep have gone astray, Each of us has turned to his own way; But the Lord has caused the iniquity of us all To fall on Him. (Isaiah 53:4-6)
On the cross, the Lord bore the punishment of our sins, not the sins themselves. He did not exchange His divine nature for Satan’s, or accept any blemish that would render Him as anything less than our spotless Lamb and perfect sacrifice. As John MacArthur explains,
Christ was not made a sinner, nor was He punished for any sin of His own. Instead, the Father treated him as if He were a sinner by charging to His account the sins of everyone who would ever believe. All those sins were charged against Him as if He had personally committed them, and He was punished with the penalty for them on the cross, experiencing the full fury of God’s wrath unleashed against them all. It was at that moment that “Jesus cried out with a loud voice, saying, . . . ‘My God, My God, why have You forsaken me?’” (Matthew 27:46). It is crucial, therefore, to understand that the only sense in which Jesus was made sin was by imputation. He was personally pure, yet officially culpable; personally holy, yet forensically guilty. But in dying on the cross Christ did not become evil like we are, nor do redeemed sinners become inherently as holy as He is. God credits believers’ sin to Christ’s account, and His righteousness to theirs. The MacArthur New Testament Commentary: 2 Corinthians, 215.
Imputation is the key; if Christ was not fully righteous in His sacrificial death, we can’t be considered fully righteous in the eyes of God. If Christ wasn’t completely sinless, there is no hope of reconciliation for us.