She was born in Genoa in 1447, and died in 1510
Of a noble family she grew up very inclined to holiness, at the age of sixteen she was given in marriage by her parents to Giuliano Adorno, and she suffered with a very difficult marriage that lasted until her husband died ten years later.
At the age of twenty six she had a great spiritual experience in which she was shown her soul the way God sees it. As a result she began a dialogue between her soul and her humanity. Guided by the Holy Spirit, she wrote what the soul experiences in Purgatory. She lived her life as a soul in purgatory , as she was being purified; she wrote her doctrine on Purgatory.
The "Dialogue," long generally accepted as Catherine's own account of her spiritual life, has been allowed by the highest authorities to embody, with her "Treatise on Purgatory," the saint's doctrine. These two treatises and the earliest biography, translated into several languages, spread that doctrine and devotion to her throughout the Catholic world in the centuries between her death and her canonisation. The bull which canonised her alludes to the "Dialogue" as an exposition of her doctrine: "In her admirable "Dialogue" she depicts the dangers to which a soul bound by the flesh is exposed."
She practiced charity during her life and helped people in a hospital.
Excerpts of "Treatise on Purgatory"
How by comparing it to the Divine Fire which she Felt in Herself, this soul understood what Purgatory was like and how the Souls there were Tormented.
The state of the souls who are in Purgatory, how they are exempt from all self-love.
This holy Soul found herself, while still in the flesh, placed by the fiery love of God in Purgatory, which burnt her, cleansing whatever in her needed cleansing, to the end that when she passed from this life she might be presented to the sight of God, her dear Love. By means of this loving fire, she understood in her soul the state of the souls of the faithful who are placed in Purgatory to purge them of all the rust and stains of sin of which they have not rid themselves in this life. And since this Soul, placed by the divine fire in this loving Purgatory, was united to that divine love and content with all that was wrought in her, she understood the state of the souls who are in Purgatory. And she said:
The souls who are in Purgatory cannot, as I understand, choose but be there, and this is by God's ordinance who therein has done justly. They cannot turn their thoughts back to themselves, nor can they say, "Such sins I have committed for which I deserve to be here ", nor, "I would that I had not committed them for then I would go now to Paradise", nor, "That one will leave sooner than I", nor, "I will leave sooner than he". They can have neither of themselves nor of others any memory, whether of good or evil, whence they would have greater pain than they suffer ordinarily. So happy are they to be within God's ordinance, and that He should do all which pleases Him, as it pleases Him that in their greatest pain they cannot think of themselves. They see only the working of the divine goodness, which leads man to itself mercifully, so that he no longer sees aught of the pain or good which may befall him. Nor would these souls be in pure charity if they could see that pain or good. They cannot see that they are in pain because of their sins; that sight they cannot hold in their minds because in it there would be an active imperfection, which cannot be where no actual sin can be.
Only once, as they pass from this life, do they see the cause of the Purgatory they endure; never again do they see it for in another sight of it there would be self. Being then in charity from which they cannot now depart by any actual fault, they can no longer will nor desire save with the pure will of pure charity. Being in that fire of Purgatory, they are within the divine ordinance, which is pure charity, and in nothing can they depart thence for they are deprived of the power to sin as of the power to merit.
What is the joy of the souls in Purgatory. A comparison to show how they see God ever more and more. The difficulty of speaking of this state.
I believe no happiness can be found worthy to be compared with that of a soul in Purgatory except that of the saints in Paradise; and day by day this happiness grows as God flows into these souls, more and more as the hindrance to His entrance is consumed. Sin's rust is the hindrance, and the fire burns the rust away so that more and more the soul opens itself up to the divine inflowing. A thing which is covered cannot respond to the sun's rays, not because of any defect in the sun, which is shining all the time, but because the cover is an obstacle; if the cover be burnt away, this thing is open to the sun; more and more as the cover is consumed does it respond to the rays of the sun
It is in this way that rust, which is sin, covers souls, and in Purgatory is burnt away by fire; the more it is consumed, the more do the souls respond to God, the true sun. As the rust lessens and the soul is opened up to the divine ray, happiness grows; until the time be accomplished the one wanes and the other waxes. Pain however does not lessen but only the time for which pain is endured. As for will: never can the souls say these pains are pains, so contented are they with God's ordaining with which, in pure charity, their will is united.
But, on the other hand, they endure a pain so extreme that no tongue can be found to tell it, nor could the mind understand its least pang if God by special grace did not show so much. Which least pang God of His grace showed to this Soul, but with her tongue she cannot say what it is. This sight which the Lord revealed to me has never since left my mind and I will tell what I can of it. They will understand whose mind God deigns to open.
Separation from God is the chief punishment of Purgatory. Wherein Purgatory differs from Hell.
All the pains of Purgatory arise from original or actual sin. God created the soul pure, simple and clean of all stain of sin, with a certain beatific instinct towards Himself whence original sin, which the soul finds in itself, draws it away, and when actual is added to original sin the soul is drawn yet further away. The further it departs from its beatific instinct, the more malignant it becomes because it corresponds less to God.
There can be no good save by participation in God, who meets the needs of irrational creatures as He wills and has ordained, never failing them, and answers to a rational soul in the measure in which He finds it cleansed of sin's hindrance. When therefore a soul has come near to the pure and clear state in which it was created, its beatific instinct discovers itself and grows unceasingly, so impetuously and with such fierce charity (drawing it to its last end) that any hindrance seems to this soul a thing past bearing. The more it sees, the more extreme is its pain.
Because the souls in Purgatory are without the guilt of sin, there is no hindrance between them and God except their pain, which holds them back so that they cannot reach perfection. Clearly they see the grievousness of every least hindrance in their way, and see too that their instinct is hindered by a necessity of justice: thence is born a raging fire, like that of Hell save that guilt is lacking to it. Guilt it is which makes the will of the damned in Hell malignant, on whom God does not bestow His goodness and who remain therefore in desperate ill will, opposed to the will of God.
Work of God Apostolate
Saint Catherine of Genoa - Doctrine on purgatory