Romans 3

Paul continues to build his case against humanity's goodness. He asks who has an advantage with God; and then gives the obvious answer - nobody. In fact, our misdeeds (either doing the wrong thing or failing to do the right thing) only prove that God is just and perfect and mankind is deserving of violating that perfection. The only hope is to obtain God's righteousness via belief in His Son, Jesus Christ. You and I are not righteous; He is infinitely righteous and offers His righteousness to those willing to accept it. The basis for boasting, then, is totally in Christ.