The public sacrifice of the Son of God on the cross was a declaration by God that he is righteous even as he justifies or declares the ungodly righteous. How can this be? Because Christ in his obedience and death satisfied the demands of God and his justice and paid for their debts. Last Lord’s day we talked about this very thing and said that God’s mercy and justice were in perfect harmony in the justification of sinners. Some have even said his mercy and justice kiss at the cross.
Unfortunately some haven’t seen it that way. One of the arguments that has been made against this teaching is that if our justification is grounded on the work of Christ and if that work satisfies the justice and wrath of God and pays for our debts then justification cannot be said to be a work of grace.
Westminster Confession 11.3
III. Christ, by His obedience and death, did fully discharge the debt of all those that are thus justified, and did make a proper, real and full satisfaction to His Father’s justice in their behalf. Yet, in as much as He was given by the Father for them; and His obedience and satisfaction accepted in their stead; and both, freely, not for any thing in them; their justification is only of free grace; that both the exact justice, and rich grace of God might be glorified in the justification of sinners.
Scripture: ROM 5:8 But God commendeth his love toward us, in that, while we were yet sinners, Christ died for us. 9 Much more then, being now justified by his blood, we shall be saved from wrath through him. 10 For if, when we were enemies, we were reconciled to God by the death of his Son, much more, being reconciled, we shall be saved by his life. 19 For as by one man’s disobedience many were made sinners, so by the obedience of one shall many be made righteous. 1TI 2:5 For there is one God, and one mediator between God and men, the man Christ Jesus; 6 Who gave himself a ransom for all, to be testified in due time. HEB 10:10 By the which will we are sanctified through the offering of the body of Jesus Christ once for all. 14 For by one offering he hath perfected for ever them that are sanctified. DAN 9:24 Seventy weeks are determined upon thy people and upon thy holy city, to finish the transgression, and to make an end of sins, and to make reconciliation for iniquity, and to bring in everlasting righteousness, and to seal up the vision and prophecy, and to anoint the most Holy. 26 And after threescore and two weeks shall Messiah be cut off, but not for himself: and the people of the prince that shall come shall destroy the city and the sanctuary; and the end thereof shall be with a flood, and unto the end of the war desolations are determined. ISA 53:4 Surely he hath borne our griefs, and carried our sorrows: yet we did esteem him stricken, smitten of God, and afflicted. 5 But he was wounded for our transgressions, he was bruised for our iniquities: the chastisement of our peace was upon him; and with his stripes we are healed. 6 All we like sheep have gone astray; we have turned every one to his own way; and the Lord hath laid on him the iniquity of us all. 10 Yet it pleased the Lord to bruise him; he hath put him to grief: when thou shalt make his soul an offering for sin, he shall see his seed, he shall prolong his days, and the pleasure of the Lord shall prosper in his hand. 11 He shall see of the travail of his soul, and shall be satisfied: by his knowledge shall my righteous servant justify many; for he shall bear their iniquities. 12 Therefore will I divide him a portion with the great, and he shall divide the spoil with the strong; because he hath poured out his soul unto death: and he was numbered with the transgressors; and he bare the sin of many, and made intercession for the transgressors.
 2CO 5:21 For he hath made him to be sin for us, who knew no sin; that we might be made the righteousness of God in him. MAT 3:17 And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased. EPH 5:2 And walk in love, as Christ also hath loved us, and hath given himself for us an offering and a sacrifice to God for a sweetsmelling savour.
 ROM 3:24 Being justified freely by his grace through the redemption that is in Christ Jesus: EPH 1:7 In whom we have redemption through his blood, the forgiveness of sins, according to the riches of his grace.
 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. EPH 2:7 That in the ages to come he might shew the exceeding riches of his grace in his kindness toward us through Christ Jesus.