Don't ever pray, "God, give me justice." You don't want God to give you what you deserve, which is judgment. Rather, a better thing to pray would be, "God, be merciful to me. God, extend your grace to me." When God extends mercy, He doesn't give you what you deserve. And when God extends grace, He gives you His unmerited favor and blessing.
The Bible tells us that it is "by grace you have been saved through faith, and that not of yourselves; it is the gift of God, not of works, lest anyone should boast" (Ephesians 2:8–9).
We find a classic example of grace in the story of the prodigal son. The son had sinned. He dragged the family name through the mud. If the father had dealt with his prodigal son justly, he would have allowed the boy to be stoned. That would have been justice.
If the father would have dealt with the son in mercy, he would have let him come on as a hired hand as the boy had requested.
But the father dealt with him in grace when he provided his son with luxurious attire and placed a signet ring on his finger. That was grace, not justice, and it was even more than mercy. It was grace extended.
It was God's grace that sustained the apostle Paul in his days of difficulty with his thorn in the flesh. Paul had some kind of physical infirmity. It may have been a disability or an injury resulting from one of his stonings or shipwrecks. Whatever it was, he asked God three times to take it away. But God told him, "My grace is sufficient for you, for My strength is made perfect in weakness" (2 Corinthians 12:9).
Grace is getting what we don't deserve.