So the Cross does not merely tell us that God forgives, it tells us that that is God’s way of making forgiveness possible. It is the way in which we understand how God forgives. I will go further: How can God forgive and still remain God? – That is the question. The Cross is the vindication of God. The Cross is the vindication of the character of God. The Cross not only shows the love of God more gloriously than anything else, it shows His righteousness, His justice, His holiness, and all the glory of His eternal attributes. They are all to be seen shining together there. If you do not see them all you have not seen the Cross.
Martyn Lloyd-Jones