In Romans Paul writes...
Rom 3:24 Being justified freely by his grace through the redemption that is in Christ Jesus:
Rom 3:25 Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
Rom 3:26 To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
Rom 3:27 Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith.
Rom 3:28 Therefore we conclude that a man is justified by faith without the deeds of the law.
Rom 3:29 Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:
Rom 3:30 Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
Rom 3:31 Do we then make void the law through faith? God forbid: yea, we establish the law.
Rom 3:24 Being justified freely by his grace through the redemption that is in Christ Jesus:
Rom 3:25 Whom God hath set forth to be a propitiation through faith in his blood, to declare his righteousness for the remission of sins that are past, through the forbearance of God;
Rom 3:26 To declare, I say, at this time his righteousness: that he might be just, and the justifier of him which believeth in Jesus.
Rom 3:27 Where is boasting then? It is excluded. By what law? of works? Nay: but by the law of faith.
Rom 3:28 Therefore we conclude that a man is justified by faith without the deeds of the law.
Rom 3:29 Is he the God of the Jews only? is he not also of the Gentiles? Yes, of the Gentiles also:
Rom 3:30 Seeing it is one God, which shall justify the circumcision by faith, and uncircumcision through faith.
Rom 3:31 Do we then make void the law through faith? God forbid: yea, we establish the law.
He declares HIS RIGHTEOUNESS provided for us through Jesus redemption and propitiation so that He can remain just and at the same time declare righteous we sinners.
Jesus was given as a propitiation (mercy seat) for us.
In other words it is through Jesus Christ that we approach God and find mercy for our past sin.
We then enter into the New Covenant via the blood in repentance and faith and our faith then UPHOLDS THE LAW because genuine faith works by love and love works no ill. The law being written upon the heart and in the mind by the Holy Ghost (love shed abroad in the heart).