One of the purposes of devotions such as the Way of the Cross seems to be that they make us realize things which we already know. Or, to put it in Bl. J. H. Newman’s terms, they give us real apprehension of truths which we tend to apprehend only notionally. Take for example mortal sin: we apprehend at least notionally that with mortal sin we oppose God. Bl. Columba Marmion states this with great force:
Sin is […] the negation by the creature of the existence of God, of His truth, His sovereignty, His holiness, His goodness. […] In voluntarily performing an action contrary to God’s will [the soul] practically denies that God is sovereign wisdom and has the power to establish laws; it practically denies the holiness of God and refuses to give Him the adoration due to Him; it practically denies that God is omnipotent and has the right of claiming the obedience of beings that receive their life from Him; it denies that God is supreme goodness worthy of being preferred to all that is not Himself; it puts God beneath the creature. Non serviam: “I know Thee not, I will not serve Thee”, says this soul, repeating the words of Satan on the day of his revolt. Does it say them with the lips? No, at least not always; perhaps it would not like to do so, but it says them in act. Sin is the practical negation of the Divine perfections […] practically, if such a thing were not rendered impossible by the nature of the Divinity, this soul would work evil to the Infinite Majesty and Goodness; it would destroy God.
He then immediately proceeds to show how this infinite malice is revealed in the passion:
And was not this what happened? When God took to Himself a human form, did not sin slay him? (Christ the Life of the Soul)
But the problem is that we tend that revelation tends in turn to be only notionally apprehended. And this is where the Way of the Cross can help us, since the contemplation of the concrete circumstances of the Passion leads to real apprehension. Thus many meditations on the Stations begin by contemplating the malice of sin. Here is Bl. Cardinal Newman’s own meditation on the first station:
Jesus is condemned to death. His death-warrant is signed, and who signed it but I, when I committed my first mortal sins? My first mortal sins, when I fell away from the state of grace into which Thou didst place me by baptism; these it was that were Thy death-warrant, O Lord. The Innocent suffered for the guilty. Those sins of mine were the voices which cried out, “Let Him be crucified.” That willingness and delight of heart with which I committed them was the consent which Pilate gave to this clamorous multitude. And the hardness of heart which followed upon them, my disgust, my despair, my proud impatience, my obstinate resolve to sin on, the love of sin which took possession of me—what were these contrary and impetuous feelings but the blows and the blasphemies with which the fierce soldiers and the populace received Thee, thus carrying out the sentence which Pilate had pronounced?