He was born
Ioan Costişte in a village in the
Principality of Moldavia (
Wallachia) to Margareta Bărbat and Stoica Costişte (Kostist), who were prosperous farmers. Few details have survived of his childhood and youth, other than that as a child he had developed the conviction that he wanted to go to Italy because that was where the best Christians were to be found. His mother told him it was a place "where the monks were all holy and there was the pope, the Vicar of Christ"; the fact that he was illiterate and knew his own dialect and no other language did not hinder his decision. At the age of 19, Costişte left home with his parents' permission to carry out his dream. After a long journey during which he served as a physician's assistant, he arrived in
Bari, Italy, where he settled at the age of 22. He began to serve the celebrated doctor Pietro Lo Iacono. After five years of life there, he determined that he was not finding what he sought; he was then resolved to go back home. After his profession of
religious vows a year later, he was assigned to a number of friaries in the province between 1579 and 1584; among those positions was in 1585 acting as a medical assistant at the Capuchin medical centre in their convent of Saint Eframo Nuovo in Naples. In 1585, Jeremiah was assigned to the infirmary of the Monastery of St. Ephrem the Old in Naples, where he would live out the rest of his life. There he cared for the sick friars of the community, as well as for the poor and sick of the city. He seemed born for this task, becoming noted for his compassion for the suffering. For him, people were "part of the suffering Jesus and he saw them like Jesus himself". He came to serve even lepers, for whom he would prepare an herbal preparation to cover the stench of their decaying flesh. Miraculous cures began to be associated with his nursing and prayers. He also cared for the insane, becoming the sole caretaker of one friar who was so violent that he drove everyone else away. He cared for that friar for nearly five years, and later called him his "recreation". Jeremiah felt such a commitment to the poverty that is a hallmark of the Franciscan Order that he is said to have spent 35 years wearing the same
habit. In a like manner, his ration of food generally went to others. On 14 August 1608, the eve of the
Feast of the Assumption, he had a vision of the Blessed Mother in which he enquired to her the reason she did not wear a crown; she responded with: "Here is my crown: my son". He confided this vision to his friend and friar Pacifico da Salerno and soon the tale spread from person to person. An artist even made an icon that depicted this event. He would refer to her as "Mammarella Nostra". In 1625, Jeremiah, by then aged 69 years, was becoming aware of his approaching death. With that his spirit of self-sacrifice grew. On 26 February of that year, a great personage at the Spanish royal court (
Torre del Greco) was seriously ill, and summoned Jeremiah to care for him. Jeremiah did not understand why he was not sent a means of transport. On a long walk from the monastery a woman tells him: :"We have to come Wednesday to the friary." :"You will have to find me." :"But where will you be?" :"I want to go to my homeland." His return to Naples witnessed him contracting
pleuropneumonia; he died of that on 5 March 1625. His final words were "Yes, Jesus, come! Thank you!" After his death he was clothed in the habit six times since the faithful snipped parts of it off for themselves as relics. He is buried in the church of the
Immaculate Conception in Naples. ==Contemporary reputation==