English Standard Version (ESV)
An amazing thing happens here in just a few verses. In verse 23, Paul is telling us that we have all sinned and fallen short. We should be in the midst of despair by the end of the sentence, but we can scarcely catch our breath before Paul is reminding us that God has justified us by his grace as a gift that is received by faith. From despair we suddenly see hope, and then Paul tells us that God passes over our sins by the blood of the Lamb (sound familiar?), all so that he can justify us.
God doesn't hide our sin from us -- he reveals it to us, but it does not have the power to grip us with despair, because God also redeems us by his blood, offering us grace and peace and freedom and love through the blood of his son, Jesus Christ. God paid the ultimate price, and so while our sin is not hidden, it is not used to condemn or destroy us, but rather to remind us of how great the love of God is!