What is the real key, what is the Christian interpretation of this world?  What is given us by revelation to estimate and measure this world by?  The event of this season: the Crucifixion of the Son of God. 

It is the death of the Eternal Word of God made flesh, which is our great lesson: how to think and how to speak of this world.  His Cross has put its due value upon every thing which we see, upon all fortunes, all advantages, all ranks, all dignities, all pleasures; upon the lust of the flesh, and the lust of the eyes, and the pride of life.  It has set a price upon the excitements, the rivalries, the hopes, the fears, the desires, the efforts, the triumphs of mortal man.  It has given a meaning to the various, shifting course, the trials, the temptations, the sufferings, of his earthly state.  It has brought together and made consistent all that seemed discordant and aimless.  It has taught us how to live, how to use this world, what to expect, what to desire, what to hope.  It is the tone into which all the strains of this world's music are ultimately to be resolved. [...]

Thus in the Cross, and Him who hung upon it, all things meet; all things subserve it, all things need it.  It is their centre and their interpretation.  For He was lifted up upon it, that He might draw all men and all things unto Him. […]  

The doctrine of the Cross does but teach, though infinitely more forcibly, still after all it does but teach the very same lesson which this world teaches to those who live long in it, who have much experience in it, who know it. […]  When a man has passed a certain number of years in it, he cries out with the Preacher, "Vanity of vanities, all is vanity". […]  Therefore the doctrine of the Cross of Christ does but anticipate for us our experience of the world. […]  It may be granted, then, that the doctrine of the Cross is not on the surface of the world.  The surface of things is bright only, and the Cross is sorrowful; it is a hidden doctrine; it lies under a veil; it at first sight startles us, and we are tempted to revolt from it. [...]  And yet it is a true doctrine; for truth is not on the surface of things, but in the depths.

St. John Henry Newman

Extract from Sermon VII (PPS, VI, 7)