How Does God's Justice Work Out in the Old and New Testaments?

In the Old Testament, God brought curses upon Israel for their sin. But in the New Covenant, Christ became the curse of the law for us. With that said, how exactly does God's justice work out across the two Testaments? To answer this question, consider the following Q&A or catechetical style of instruction.

1. Why did God afflict Israel? "Because of the abundance of her sins" (Lam 1:5).

1. Why was affliction God's mode of action? Because of the covenant with Israel (Lev 26; Deut 27–30).

1. Does God afflict Christians today? He disciplines us, yes, but Christ suffered for our sins punitively.

1. Why does God discipline Christians? Because "the Lord disciplines the one he loves" (Heb 12:6).

1. Why is discipline God's mode of action? For "discipline" or paideia (Heb 12:7).

1. What does paideia mean? Paideia means educating and upbringing someone for their good.

1. Did God ever discipline any Old Covenant believers in this way? Yes, but not according to the Mosaic covenant but according to grace and to his love for his creation.

1. How does our discipline contrast with Israel's affliction? God punishes Jesus in our place so that we can receive paideia in the New Covenant, while God brought curses on Israel according to the stipulations of the Old Covenant. 

In summary, God's manifestation of justice in the Old Covenant follows his covenantal obligations to bring curses upon Israel when they sin. Since Christ took the curse for us and abolished the Old Covenant, now we have a New Covenant. In the New Covenant, God disciplines us for our growth. In the Old Covenant, God cursed Israel because of the covenant's stipulations.