The more we emphasize the inflexible demands of justice and holiness the more marvellous become the love of God and its provisions.
This quote was in the context of the necessity for the atonement. As a person still in their 20's this quote strikes me as one that would offend a lot Christian young people today. God's love is paramount, for above any other attribute they'd say. Talk about holiness and justice and you would risk being labelled a legalist! God's love is clung to while all other attributes, like holiness and justice (righteousness) are left behind. But what Murray points to here is that God's love is truly appreciated when viewed alongside His holiness and justice. These attributes show just how undeserving His love is to sinners like us. Abandon these other attributes and His love begins to lose it meaning.