Simul justus et peccator

simul justus et peccator. In what sense is this true one may ask? In accordance to the law, which are commands of that which we are to do perfectly, which we fail to do perfectly as God is holy so we are to live holy the elect Christian is a sinner. Never is he accepted by God on the basis of his law keeping. Neither can he find his assurance in his law keeping for he cannot keep the law perfectly. But rather on the basis of Christ's imputed righteousness to the elect is the elect sinner justified. So the Christian's righteousness is grounded on a righteousness not their own but on an alien righteousness won by Christ alone. And on the basis of the law he is yet still a sinner never attaining that good that he ought to do. So the Christian is simultaneously just and sinner at the same time. We see how the two forms of righteousness relate to the law and gospel distinction.

The Two Forms of Righteousness

"Both the law-gospel and the passive/active-righteousness distinctions are essential for the Lutheran pastor, and neither needs to be neglected in favor of the other. Law and Gospel remind us that Christians always fall short of God's will and are saved solely by God's grace. The two kinds of righteousness remind God's people that they cannot work to merit God's favor or love, but that righteousness is given freely, and that they are called to live holy lives in the world for the sake of others." - Jordon Cooper, Hands of Faith, pg. 128