Welcome to where things do not make sense in the real world.
This is the incredible. The awesome. The audacious.
Let us chop this verse up.
Who is he who made him to be sin?
He is God the Father. Sovereignly gracious. The Changer of destiny. The Chooser of the saved. The Adopter of the lost. The Savior of the man. Mindful of all. Source of all truth.
Who is him who knew no sin that was made to be sin by God?
He is Christ, the Son of God. Love overflowed. The gap between heaven and earth. The bridge between God and man. The bearer of our sorrows. The holder of our transgressions. The One who will make all things right.
What is sin?
Traitorous acts by creatures against the Almighty Creator. The breaking of God’s law that resulted in our disconnect to God by God from God for God and the decay, destruction, diseased, and death of the universe and everything within it.
Who are we?
Those who were foreknown by God, elected by God, called by God, atoned by God, whose wrath of God absorbed by God, whose sin is removed by God, adopted by God, set aside by God, nurtured by God, disciplined by God, raised by God to the glory of God forever.
What is the righteousness of God?
It is the perfection of God. This is not a standard that you can achieve through good moral behavior nor is this a grade that you can get to by maxing out every achievement. This is who God is, what he has done, what He thinks like, what He will do from eternity past to eternity present. Nothing you can ever do will give you enough points to make you righteous like him.
So how can I be in Him in order to become the righteousness of God?
Give him everything. Your trust. Your doubts. Your fears. Your worries. Your hurts. The pain you have caused. The troubles you have stirred up. The blasphemous thoughts you have thought. The good you failed to do. The bad you have done and will ever done. You give it all to him. You tell Christ, “This is the best I can do. This is now yours. Do with it what you must.”
Here is the exchange—the Great Exchange: Christ, in his perfection, sinless, holiness self, takes the best of what you have—your sin—and removes it all from you. In turn, Christ will always give you His perfection, hope, faith, righteousness, holiness, grace, mercy, tenderness, kindness and love.
In short, the question is “What is imputation?” or “How does God give everything that He has for everything that you have?”
Answer: That is love.