16 From now on, therefore, we regard no one according to the flesh. Even though we once regarded Christ according to the flesh, we regard him thus no longer. 17 Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come. 18 All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation; 19 that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation. 20 Therefore, we are ambassadors for Christ, God making his appeal through us. We implore you on behalf of Christ, be reconciled to God. 21 For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God.
That's from the Bible, Paul's second letter to the Corinthians, chapter 5.
Look it up for yourself and you'll see—you can be right with God! Not because of anything you've done, but because "For our sake he made him to be sin who knew no sin, so that in him we might become the righteousness of God."
Once you unpick the complexity of the grammar, you pretty much understand that Jesus did everything right, we did everything wrong, but what he did has been credited to us in the very deepest way that it is possible for such a thing to happen.