When God's righteousness is mentioned in the gospel, it is God's action of declaring righteous the unrighteous sinner who has faith in Jesus Christ. The righteousness by which a person is justified (declared righteous) is not his own but that of another, Christ.
Martin LutherThe bible is a remarkable fountain: the more one draws and drinks of it, the more it stimulates thirst.
Martin LutherFor it is a horrible blasphemy to imagine that there is any work by which you should presume to pacify God, since you see that there is nothing which is able to pacify Him but this inestimable price, even the death and the blood of the Son of God, one drop of which is more precious than the whole world.
Martin Luther