Rev 15:3-4, Isa 53:6, 2 Cor 5:21, Gal 3:13, 1 Pt 2:22-24, Rom 4:24-25, Rom 8:3-4

God is a God of justice. (Deut 32:4)

Deut 32:4 He is the Rock, his work is perfect: for all his ways are judgment: a God of truth and without iniquity, just and right is he.

Moses praised God who would accomplish justice through Christ. (Rev 15:3-4)

Rev 15:3 And they sing the song of Moses the servant of God, and the song of the Lamb, saying, Great and marvellous are thy works, Lord God Almighty; just and true are thy ways, thou King of saints. 4 Who shall not fear thee, O Lord, and glorify thy name? for thou only art holy: for all nations shall come and worship before thee; for thy judgments are made manifest.

In the Old Testament, God promised to fulfill God's justice toward us by having Christ die for us. (Isa 53:6)

Isa 53:6 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.

Jesus took our sins and died on the cross to fulfill God's justice for us. (2 Corinthians 5:21, Gal 3:13, 1 Pet 2:22-24, Romans 4:24-25, Romans 8:3-4)

2 Corinthians 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.

Gal 3:13 Christ hath redeemed us from the curse of the law, being made a curse for us: for it is written, Cursed is every one that hangeth on a tree:

1 Pet 2:22 Who did no sin, neither was guile found in his mouth: 23 Who, when he was reviled, reviled not again; when he suffered, he threatened not; but committed himself to him that judgeth righteously: 24 Who his own self bare our sins in his own body on the tree, that we, being dead to sins, should live unto righteousness: by whose stripes ye were healed.

Romans 4:24 But for us also, to whom it shall be imputed, if we believe on him that raised up Jesus our Lord from the dead; 25 Who was delivered for our offences, and was raised again for our justification.

Romans 8:3 For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh: 4 That the righteousness of the law might be fulfilled in us, who walk not after the flesh, but after the Spirit.