St. Faustina was one of the greatest mystics of the 20th century, and perhaps of Church history in general.
“Today I was in heaven, in spirit,” she wrote in her diary on November 27th, 1936, “and I saw its inconceivable beauties and the happiness that awaits us after death.”
As with all of her visions, what she saw constitutes “private revelation,” and is thus not binding on the Catholic faithful, as public revelation (Scripture and Tradition) is. Nonetheless, it can aid in building up one’s faith.
Here’s what she saw:
“I saw how all creatures give ceaseless praise and glory to God. I saw how great is happiness in God, which spreads to all creatures, making them happy; and then all the glory and praise which springs from this happiness returns to its source; and they enter into the depths of God, contemplating the inner life of God, the Father, the Son, and the Holy Spirit, whom they will never comprehend or fathom.
“This source of happiness is unchanging in its essence, but it is always new, gushing forth happiness for all creatures. Now I understand Saint Paul, who said, ‘Eye has not seen, nor has ear heard, nor has it entered into the heart of man what God has prepared for those who love Him.'”
She then writes about what God values most:
“And God has given me to understand that there is but one thing that is of infinite value in His eyes, and that is love of God; love, love and once again, love; and nothing can compare with a single act of pure love of God. Oh, with what inconceivable favors God gifts a soul that loves Him sincerely!
“Oh, how happy is the soul who already here on earth enjoys His special favors! And of such are the little and humble souls.”
She also reports that the sight of God in heaven didn’t bring her fear, but joy:
“The sight of this great majesty of God, which I came to understand more profoundly and which is worshiped by the heavenly spirits according to their degree of grace and the hierarchies into which they are divided, did not cause my soul to be stricken with terror or fear; no, no, not at all!
“My soul was filled with peace and love, and the more I come to know the greatness of God, the more joyful I become that He is as He is. And I rejoice immensely in His greatness and am delighted that I am so little because, since I am little He carries me in His arms and holds me close to His Heart.”
She said the whole experience made her pity those who don’t believe in heaven:
“O my God, how I pity those people who do not believe in eternal life; how I pray for them that a ray of mercy would envelop them too, and that God would clasp them to His fatherly bosom.
“O Love, O queen! Love knows no fear, It passes through all the choirs of angels that stand on guard before his throne. It will fear no one. It reaches God and is immersed in Him as in its sole treasure. The Cherubim who guards paradise with flaming sword, has no power over it. O pure love of God, how great and unequaled you are!
“Oh, if souls only knew your power!” (Diary: Divine Mercy in My Soul, 777-781)