So much more becomes evident when considering Mary's role as Mediatrix of all graces. Without mercy there is no salvation. Without mercy there is no forgiveness. Without being aware that God desires to give mercy who would know to seek it? Having to face God's judgement one day Our Lady's intercession for mercy is the only way to receive Her Son's advocacy before the Father.
Up till the moment of judgement a soul has been kept out of the pit by the intercession of the saints/martyrs until it can stand on its own feet. Our saints extended the sufferings of Christ in their own bodies to keep visible the Passion of Christ in the world. Receiving the Sacraments, the pewsitter, through their merits, continues to receive the direct outpouring of Our Lord's salvific sacrifice into the soul because they carried on as other Christs on the way to Calvary. They extend Our Lord's visible life on earth with divine Charity. Purgatory then remains the final aid to union in and with Christ in eternity.
After all, one must do something for oneself!
It seems that one can do purgatory on earth. This is where the devil can be of great assistance. Justly accusing the sinner of his sins before the throne of His Majesty, Our Lord permits said sinner to make answer.
"What do you have to say for yourself?" He is asked.
Trembling in his shoes with the Fear of God* he has no defence. He can only beg for for mercy since he is guilty as charged.
"Would you like to do something about that before you die?" He is asked
"Yes, I would, but I want to do it for love of Thee, not because I am terrified of Thee."
"For that you must have the divine gift of Charity."
"Well, keep up your devotion to my Mother, and She will help you."
Begging the intercession of Mary to guide the poor soul through this period the devil is permitted to accuse it directly. Let it defend itself under these now controlled circumstances. Having invoked God's mercy, obtained only through Mary, the poor soul is now armed with an unassailable weapon. Submitting to the trial he is permitted to experience the true state of his soul. Without mercy no man can bear this knowledge. If the need for mercy is ignored too long a soul despairs unable to bear the sight of its own sinful state where no flicker of grace remains. Unable to offer any justification for its sins Mercy alone turns the tables. Lucifer now becomes the instrument used by God for the soul's redemption. With the conviction of God's mercy the soul is enabled to fight back - to stand on its own feet.
Through varying degrees of interior suffering according to the extent it seeks out its sins, and uses the gift of divine Charity, the soul submits willingly to its just punishment, being further graced with a deeper knowledge and understanding of the price Our Lord paid for its salvation>true contrition>true sorrow>full redemption.
Pacing itself, the grace of perseverance, when sought, converts sinners into saints. In the end the great saints achieved eternal peace because the devil's just accusations had no value when the soul was fully submerged in the redeeming action of Mercy through Our Lady's continuous intercession. They overcame the devil's accusations, fully redeemed by the sufferings of Our Lord transforming them....for if God forgives who can condemn? It is this latter information that the angel of darkness tries desperately to block the soul from contemplating. After Christ's crucifixion, when it was too late, he knows better than any sinner that God is indeed merciful to the repentant heart - that he has no leg to stand on if the soul were to believe this. So the trials endured are Lucifer's attempts to frighten and panic. Permitted to experience and endure these trials purges the soul with the result that, bit by painful bit, the soul is delivered of its sinful state at the same time growing in grace and Charity.
The power of Mercy is boundless; the power of Mary is boundless. As already stated, without Mercy we remain in our sins - unredeemed and destined for hell. One cannot cease contemplating the Wisdom of our God for if Lucifer had known that one can only be redeemed through Mary's intercession, then would he not have targetted our Blessed Mother for crucifixion?
...[Mary] merited to become most worthily the Reparatrix of the lost world, ...Dispensatrix of all the gifts that Our Savior purchased by His Death and His Blood... (and) it has been allowed to the august Virgin to be the most powerful mediatrix and advocate of the whole world with Her Divine Son' (Pius IX, Ineffabilis Deus)." 3 Hence, St. Pius X continues, "far from attributing to the Mother of God a productive power of grace --- a power which belongs to God alone, yet... She merits 'de congruo' what Jesus Christ merits for us 'de condigno', and She is the supreme minister of the distribution of graces. Jesus 'sitteth on the right hand of the majesty on high' (Hebrews 1:3). Mary sitteth at the right hand of Her Son --- a refuge so secure and a help so trusty against all dangers that we have nothing to fear or to despair under Her guidance, Her patronage, Her protection. (Pius IX, in the Bull Ineffabilis Deus)." (An extract from : Only She Can Help You)
* Should sinner be fortunate to have received the gifts of the Holy Spirit through Baptism and Confirmation.