Enduring the pain and suffering from a losing battle with cancer, a nun from Argentina still showed a radiant, smiling face for days until she breathe her last on June 22. She was 43.

Images showing Sister Cecilia's wondrously joyful face with nary a hint of pain circulated on social media over the weekend, filling readers with awe and wonder as they shared the images and their heartfelt prayers.

Even Pope Francis was moved by her images and story and assured her of his prayers. In a voice message, the pope told her that he knew of her offering and that he loved her very much.

Behind the images of Sister Cecilia is an even gripping and inspiring story about this young Carmelite nun as originally published in the Spanish-language edition of the Aleteia news site. Her images and the accounts about her life can also be viewed from the Facebook page Curia General de los Carmelitas Descalzos.

Translating the accounts on Sister Cecilia into English, Aleteia says those who knew her and witnessed her suffering attest that the nun's testimony of joy and peace in her life was just as radiant as her face.

Sister Cecilia Maria lived at a monastery in Argentina, dedicated to a life of contemplative prayer. At the monastery, she played the violin and was known for her sweetness and constant smile.

She took up nursing and earned her degree at the age of 26. She then decided to be a nun, making her final profession of faith in 2003.

Last January, she was diagnosed with cancer of the tongue. The disease quickly metastasized into her lungs.

Despite her illness, she remained joyful and at peace in appearance as she lay in bed, surrounded by numerous family members who showered her with love and affection. For instance, her nieces and nephews gathered at the hospital garden sent her messages and helium balloons and entertained her from the window of her hospital room.

Despite her condition, she put on her habit and participated at Mass in the hospital chapel.

"Those who saw her spoke of her face as showing peace and joy — as someone awaiting the encounter with the One to whom she had given her life, Our Lord Jesus Christ," Aleteia says.

Last May, Sister Cecilia, unable to speak because of her condition, wrote these words, originally in Spanish, on a piece of paper: "I am very content, astonished by the work of God through suffering, and by so many people who pray for me."

Hours before she died, the Carmelite was still able to receive Communion. She also wrote her last request: "I was thinking about how I would like my funeral to be. First, some intense prayer and then a great celebration for everyone. Don't forget to pray but don't forget to celebrate either!"

According to the Catholic News Agency, the discalced Carmelites announced her death as follows: "Jesus! Just two lines to let you know that our dearly beloved sister gently fell asleep in the Lord, after such a painful illness, always borne with joy and her surrender to her Divine Spouse. We send you all our love, grateful for your support and prayer during this entire time, so painful yet so wonderful at the same time. We believe she flew directly to heaven, but we also ask you to not cease commending her to your prayers, so from heaven she may repay you. A big hug from her Sisters in Santa Fe."