God is just…this gives us our terror at first; but is it not marvellous that this very same belief that God is just, becomes afterwards the pillar of our confidence and peace! If God be just, I, a sinner, alone and without a substitute, must be punished; but Jesus stands in my stead and is punished for me; and now, if God be just, I, a sinner, standing in Christ, can never be punished. God must change His nature before one soul, for whom Jesus was a substitute, can ever by any possibility suffer the lash of the law.
–Charles Spurgeon, MORNING AND EVENING: DAILY READINGS (Morning, September 25)
One of God’s attributes is that he is just. Being just is part of his very nature. That he is just demands that God not allow sin to go unpunished. For those who are without Christ, that is a frightening truth. These are left to receive the wrath of God upon themselves.
But how differently it is for the Christian. Christ has born our punishment upon himself. When looking up those who are in Christ, God sees them clothed in the righteousness of Christ rather than in their filthy rags.
Since our punishment has been absorbed by Christ, we no longer fear that God is just. Rather we depend upon it.