The whole of Christ, in his adorable character as the Son of God, is by himself made over to us most richly to enjoy. His wisdom is our direction, his knowledge our instruction, his power our protection, his justice our surety, his love our comfort, his mercy our solace, and his immutability our trust. He makes no reserve, but opens the recesses of the Mount of God and bids us dig in its mines for the hidden treasures. "All, all, all are yours,” saith he, “be ye satisfied with favour and full of the goodness of the Lord." - Spurgeon
God's justice is such a huge deal throughout the Old Testament. Certainly many other attributes show up as well, but the nation of Israel is such a massive object lesson in what happens when God's holiness combined with his just nature is despised.
And with that in mind, the Gospel becomes so much more meaningful. In salvation, the justice of God, which was once our mortal enemy, now works on our behalf for our benefit. It was not only removed from us, but it is promised to us for our enjoyment and blessing. And what wonder that it is given for us based on no merit or work of our own!
As regards the gospel, [the Jews] are enemies for your sake. But as regards election, they are beloved for the sake of their forefathers. For the gifts and the calling of God are irrevocable. For just as you were at one time disobedient to God but now have received mercy because of their disobedience, so they too have now been disobedient in order that by the mercy shown to you they also may now receive mercy. For God has consigned all to disobedience, that he may have mercy on all. Oh, the depth of the riches and wisdom and knowledge of God! How unsearchable are his judgments and how inscrutable his ways!
"For who has known the mind of the Lord, or who has been his counselor?"
"Or who has given a gift to him that he might be repaid?"
For from him and through him and to him are all things. To him be glory forever. Amen. - Romans 11:28-36