God's holiness and righteous glory have been desecrated, defamed, and blasphemed by our sin. It is with a holy God that we have to do in our guilt! And there can be no justification, no reconciliation, no cleansing of our conscience, unless the holiness of God is honored and the defamation of His righteousness is repaired. The urgency of our problem with guilt is not that we feel miserable, but that God's name has been blasphemed. We live in a day with such a horrendously inflated view of human potential and such a miserably tiny view of God's holiness that we can scarcely understand what the real problem of guilt is. The real problem is not, 'How can God be loving and yet condemn people with such little sins?' The real problem is, 'How can God be righteous if He acquits such miserable sinners as we?' There can be no lasting remedy for guilt which does not deal with God's righteous indignation against sin. That's why there had to be a sacrifice. And not just any sacrifice, but the sacrifice of the Son of God! No one else, and no other act, could repair the defamation done to the glory of God by our sins. But when Jesus died for the glory of the Father, satisfaction was made. The glory was restored. Righteousness was demonstrated. Henceforth it is clear that when God, by grace, freely justifies the ungodly (Romans 4:5), He is not indifferent to the demands of justice. It is all based on the grand transaction between the Father and the Son on the morning of Good Friday at Calvary. No other gospel can take away our guilt because no other gospel corresponds to the cosmic proportions of our sin in relation to God.
John Piper