For many Christians this is a familiar passage, or at least parts of it are familiar. This is a section of scripture that usually finds it's way into references to salvation or particular techniques for evangelism. While this is not necessarily bad, taking scripture verses out of context can give us an incomplete picture of the topic at hand. In this case the topic is redemption.
Paul has been addressing Jewish believers and pointing out that while their heritage is important, it does not give them an instant "in" with God. Having the Torah (Law) is not the same as living the Torah. Living according to the Torah in its entirety, Paul says, is impossible. Everyone falls short regardless of their faith background and tradition.
If that were the end of the story--everyone falls short--it would be bad news, not good news. But Paul does not stop there. He says not only has everyone fallen short, but everyone is justified freely by God's grace presented to us in the person of Jesus the Messiah. Paul tells the Jewish believers that God has made Jesus to be the Kapparah for the whole world.
When we read verses like Romans 3:25, " God put Yeshua forward as the kapparah for sin through his faithfulness in respect to his bloody sacrificial death," it is easy to forget that we are not talking about brutish oppression of one member of the God-head by another. God the Father and Jesus the Son are one. Their will is one will. Their purpose is one purpose. All of God (Father, Son, and Holy Spirit) willed together that they should become the atoning sacrifice for the sin of the whole world in the person of Jesus the Messiah.
The picture is not one of God the Father sending Jesus to the cross, but a beautiful image of God stepping out of heaven to bear the cost of forgiveness on our behalf. This is something we understand all too well. Forgiveness requires the forgiver to bear the cost. That is what forgiveness is: choosing not to force repayment by one who has wronged us. When a bank forgives a loan they bear the financial cost. When we forgive one another we bear an emotional cost, and it hurts. When God chose to forgive the sin of all humanity for all time, he bore the physical cost: death.
This act of bearing the cost of forgiveness lifts the burden of repaying an impossible debt. It sets us free from trying to pretend we are righteous. When we accept this gift, it sets God free to bring healing into our lives. It becomes a thing that is not about us or what we do, but about God and what he has done on our behalf.
This is why there is no more boasting. This is why there is no need to put on a holy church face. This is why we can embrace those still under the impression that they are slaves to sin. We have all fallen short of perfection, and have been forgiven and cleansed by God's sovereign choice to bear the cost of forgiveness himself so that we could be restored to a right relationship with him.