As Murray has shown us this week, not only was the sacrifice of the Son of God necessary for our forgiveness and justification, and not only was it necessary as the supreme demonstration of the love of God, but, as Murray goes on to explain, this costly sacrifice was necessary on account of the vindicatory justice of God. The incomprehensible gravity and atrociousness of our sin necessitated it.
He writes, “Sin is the contradiction of God and he must react against it with holy indignation (cf. Deut. 27:26; Nahum 1:2; Rom. 1:17; 3:21-26; Gal 3:10, 13). It is this inviolable sanctity of God’s law, the immutable dictate of holiness and the unflinching demand for justice, that makes mandatory the conclusion that salvation from sin without expiation and propitiation is inconceivable. It is this principle that explains the sacrifice of the Lord of glory, the agony of Gethsemane, and the abandonment of the accursed tree. It is this principle that undergirds the great truth that God is just and the justifier of him that believeth in Jesus. For in the work of Christ the dictates of holiness and the demands of justice have been fully vindicated. God set him forth to be a propitiation to declare his [own] righteousness” (18).
No judge who lets a guilty man go free could ever be considered just. But Christ, in bearing our penalty in his body, provided the only way by which God could be both just and our justifer. The balance of these two truths is crucial, friend. For if God were only just, but not merciful, we would be without hope and forever condemned. But if God were only merciful in our justification, but not interested in justice, then grace would be cheap, and the precious Son of God will have died for no reason.