Our Lord's and Our Lady's Messages to countless Saints has been crystal clear for a long time, from St. Bridget to St. Catherine to St. Margaret Mary to St. Faustina to St. Padre Pio to several others: believe in Purgatory, be converted to a life of holiness, strive to deliver many of the Holy Souls there, and make many sacrifices for their hasty release.
https://www.michaeljournal.org/articles/roman-catholic-church/item/a-manuscript-of-a-soul-in-purgatory
"A suffering soul in Purgatory to Sister M.
If you could only know what I suffer! Pray for me, please. I suffer intensely everywhere. My God, how merciful You are! No one can imagine what Purgatory is like. Be kind and take pity on the poor souls.
May 1874. I have been in the second Purgatory since the Feast of the Annunciation. On that day I saw the Blessed Virgin for the first time. In the first stage, we never saw her. The sight of her encourages us and this beloved Mother speaks to us of Heaven. While we see her, our sufferings are greatly diminished.
You do well to pray to St. Michael and to urge others to do so. One is indeed happy at the hour of death when he has had confidence in some of the saints. They will be his protectors before God in that terrible moment.
Make it a practice to live in the presence of God with a pure intention. God seeks devoted souls who will love Him for His own sake. These are very few. He wants you to be one of His true friends. Many think they love God, but they love Him for their own sakes.
February 1875. Watch carefully over your interior life. Keep all your small troubles for Jesus alone. He is well able to make up to you for whatever He takes from you. Your life must be one of unceasing interior acts of love and of mortification, but God alone must know of it. Do nothing extraordinary. Lead a very hidden life, yet one closely united to Jesus.
Love God very much. How happy are the souls that do this. They possess a treasure! The great penance of your life will be, not the absence of your Jesus but great sorrow for all the pain you have given Him, by your failure to love Him as you desire, in return for the overwhelming number of graces which He has showered upon you and which He will continue to shower upon you.
Love everyone, but do not put your trust entirely in anyone, because Jesus wants to be your great confidant. Everything for Him and for Him alone. Perform all your actions in the presence of God as I have so often told you. Consult Him before all you do or say. Let your life be one of faith and love... Do nothing to distinguish yourself. Without offending anyone, avoid the company of those who are too unreserved and those who are uncharitable. As for yourself, be busy about your own affairs. Keep your opinions to yourself and never express them unless obliged to do so. Be preoccupied with only that one subject, the mainspring of your life, Jesus.
December 8, 1875. Love God intensely. Do not fear your own suffering. Trust in Him, never in yourself. Die to yourself from morning to night... Do not breathe or live except for Jesus Christ. God must be your only confidant. Complain to no one except for Him. Be quite hidden from the eyes of everyone else.
Feast of the Annunciation. When God wishes a soul to be entirely His, He begins by crushing it, very much as apples are crushed in the press—to extract its passions, its self-seeking, in a word, all its defects. When a soul is sufficiently broken, He reshapes it according to His will. If it is faithful, it is soon transformed. Only then does Jesus load it with His choicest graces and inundate it with His love.
Jesus wants you to deal with Him, as with an intimate friend, without any fear whatsoever. It is true that His Majesty is frightening and that you are not worthy to have such intimate converse with your Jesus, but is He not the Master that enriches whomsoever He wills? Ask Jesus to make you rich in every virtue, as He wishes you to be, but in the meantime, shape your life in accordance with His inspirations. Enlarge your heart because what Jesus desires above all things is to see in it His love. What wonderful graces you will receive if you are faithful, graces you have never even thought of.
May 12th. Mortify yourself corporally, but more especially spiritually. Forget yourself. Deny yourself in everything. Never look at what others are doing. God does not demand the same perfection from everyone. All are not enlightened in the same way, but you, whom Jesus Himself enlightens, look only to Him, let Him be your aim and object in everything.
Never grow weary in your work. Begin each day as if you had so far done nothing. This continual renouncement of one’s will and comfort and one’s own opinions is a long martyrdom, but it is most pleasing to God. God wants you to be something special, not as regards your exterior, but in your inner soul. He asks of you a union with Himself, so great that you never lose sight of Him, even amidst your absorbing occupations.
While on earth one truly cannot picture or imagine what God really is, but we (in Purgatory) know and understand Him for what He is, because our souls are freed from all the ties that fettered them and prevented them from realizing the holiness and majesty of God, and His great mercy. We are martyrs, consumed as it were by love. An irresistible force draws us towards God who is our center, but at the same time another force thrusts us back to our place of expiation. We are in the state of being unable to satisfy our longings. Oh, what a suffering that is, but we desire it and there is no murmuring against God here. We desire only what God wants. You on earth, however, cannot possibly understand what we have to endure.
Be ingenious in mortifying yourself and in breaking your own will. Be especially nice to those who are less agreeable to you than to others, no matter what wrong they may have done to you. This means renouncing yourself and pleasing Jesus. Nothing else matters. It is on these occasions that you must silence the human will, but you must do it because Jesus wills it. Do not allow self-love to get the upper hand, but do all blindly to please Jesus alone.
St. Michael
1879, Retreat in September. We see St. Michael as we see the angels. He has no body. He comes to get the souls that have finished their purification. It is he who conducts them to Heaven. He is among the Seraphim as Monsignor said. He is the highest angel in Heaven. Our own Guardian Angels come to see us but St. Michael is far more beautiful than they are. As to the Blessed Virgin, we see her in the body. She comes to Purgatory on her feasts and she goes back to Heaven with many souls. While she is with us we do not suffer. St. Michael accompanies her. When he comes alone, we suffer as usual. When I spoke to you of the great and the second Purgatory, it was to try and make you understand that there are different stages in Purgatory. Thus I call that stage of Purgatory great or worst where the most guilty souls are, and where I stayed for two years without being able to give a sign of the torments I was suffering. The year you heard me groaning, when I began to speak to you, I was still in the same place.
In the second Purgatory, which is still Purgatory but very different from the first, one suffers a great deal, but less than in the great place of expiation. Then there is the third stage, which is the Purgatory of desire, where there is no fire. The souls who did not desire Heaven ardently enough, who did not love God sufficiently, are there. It is there that I am at this moment. Further, in these three parts of purgatory, there are many degrees of variation. Little by little, as the soul becomes purified, her sufferings are changed.
The more a soul loves Jesus the more meritorious all its actions are in His sight. It is only love that will be rewarded in Heaven. All that is done for any other motive will count as nothing. Love Jesus truly, once and for all, as He wants you to. Then I also shall benefit in that I shall have great relief in all my sufferings.
Is God not more pleased with me these last few days? Yes, He is more pleased because you are striving more to give Him pleasure. Have you noticed His goodness and special watchfulness over you? Has He not also given you much joy these days? He will always act like that towards you. The more you do for Him the more He will do for you. I am so happy to see that you are really beginning to love God, who is so good, and to work seriously at your perfection. If by remaining a little longer in Purgatory I could obtain that you should arrive at perfection God demands of you to accomplish His designs, I would willingly bear that suffering. Never look back to examine your conduct in the past. Leave it entirely in the hands of God and go steadily forward. Your life must be summed up in two words: Love and Sacrifice. Sacrifice from morning to night, but always with Love. If only you knew what God is, there is no sacrifice that you would not be willing to make, no suffering that you would not endure for Him. If you could see Him for but one minute you would be perfectly satisfied and consoled... What then must it be to see Him for all eternity?
What is the best way of honoring St. Michael? The best and most efficacious way of glorifying him in Heaven and honoring him on earth is to spread devotion to the souls in Purgatory, and to make known the great mission he fulfills towards these suffering souls. It is he who is entrusted by God to lead the souls to the place of expiation and to bring them to their eternal home after purification. Each time a soul arrives to increase the number of the elect, God is glorified, and this glory in some way communicates itself also to the celestial minister. It is an honor for him to present to Our Lord the souls that will sing their thanks and His mercies through all eternity. I could never make you understand the intense love which the Heavenly Archangel has for his Divine Master, and the love which God in His turn has for St. Michael. Neither can I convey to you a true idea of the love and pity St. Michael has for us. He encourages us in our sufferings by speaking to us of Heaven.
How do they celebrate the feast of St. Michael in Purgatory? On that day St. Michael comes to Purgatory and returns to Heaven with a great number of souls, especially with those who had been devout to him in life."