Why can God forgive?

Lutero says,

De Maria,

Thanks for the comments:

Why can God forgive? In Paul’s words these terms are similar: “not counting our trespasses”, “counting righteousness”, “forgive”, “declare righteous”. The same is true in the context of 1 John 1:7-2:2). How can God forgive all our unrighteous and exact upon us the due punishment of sin? The basis is found outside of us as John explains: “the blood of Jesus His Son cleanses us from all sins (1 John 1:7)… we have an advocate with the Father, Jesus Christ the righteous One, and He Himself is the atoning sacrifice for our sins (1 John 2:2)”… How can God declare us righteous? How can God forgive us and not execute judgment? The answer to that question lies not in the inherent qualities of the wicked (or the sinner) but it lies in the Savior of the Sinner, the Righteous One, who is our atoning sacrifice for our sins. It is not “our work” that justified us but it is the “good work of Jesus 

• De Maria says:

  
  

  That is Catholic Teaching. We do not justify ourselves. But answer this question. Who is justified by God? The man who continues in sins (1 Corinthians 6:9)? Or the man who claims to have faith alone (James 2:14)? Or rather, is it the man who repents from sin and begins to keep the Commandments (Romans 2:13)?
  
  

  This is the answer. We are not justified by our works. But unless we do the works of God, keeping the Commandments, God will not shed His mercy upon us. God will not justify the unrepentant sinner (Ex 20:6; Titus 3:5; Rev 22:14).
  
  

  Sincerely,
  
  

  De Maria