The holiness of God is a deeper revelation in the cross than His love; for it is what gives His love divine value. And it is meaningless without judgement. The one thing He could not do was simply to wipe the slate and write off the loss. He must either inflict punishment or assume it. And He chose the latter course, as honouring the law while saving the guilty. He took His own judgement. It was a course that produced more than all the effect of punishment, and in a better, holier way. It was vindicative and not vindictive. It re-established the holiness; it did not just confound the sinner. Expiation, therefore, is the very opposite of exacting punishment; it is assuming it. Nor is it exacting the last farthing in any quantitative sense. That is not required in a full, true, and sufficient satisfaction. The holy law is satisfied by an adequacy short of equivalency, by due confession of it and not by exaction; by due confession which fully gauges the whole moral situation, as neither sin nor love alone could do; by practical confession in an experience as holy to God as it was sympathetic to man; and by practical confession of God's holiness far more than man's guilt. What a holy God requires is the due confession of His holiness before even the confession of sin.
P T Forsyth, in The Cruciality of the Cross, pages 205-6