Acutis spent nearly eight years at the Tommaseo Institute, a Catholic elementary and middle school run by the Marcelline Sisters in central Milan. Located just across the street from his parish church of Santa Maria Segreta, the school became the setting for his daily routine of classes, soccer games with friends in the courtyard, and visits to the chapel to pray.

“What is striking in his report cards … is that religion was the only subject he did well in,” Ceroni said. “He was someone who liked to be involved in the classroom conversations, especially in religion,” she added.

“He was also a real joker,” she added, recalling some of the pranks he played with his classmates.

The Acutis family hired a tutor named Elisa to help Carlo with his homework, and Carlo would sometimes invite Elisa her to come with him to Mass afterward. Elisa, like so many others in Carlo’s life, later said that she grew in her faith because of her relationship with Carlo.

His teachers also noticed that Carlo gravitated toward classmates who struggled or were left out.

Sister Miranda Moltedo, who was the principal of Carlo’s elementary school when he was a student, recalled a boy in the class whose mother had abandoned him. “Carlo had taken him under his wing, protecting him,” she said. “We knew that he was a child who needed special attention, affection, and love, and Carlo cared about him.”

Carlo also stood up to bullies. When a classmate with mental disabilities was being teased and bullied, Carlo defended him. A teacher observed that, as a result, sometimes that classmate could be overly clingy with Carlo. When she the teacher asked Carlo about it, he replied: “He is a great friend of mine, and I want to help him.”

“I think this ability to be inclusive as an 11- or 12-year-old boy was extraordinary. … It was a natural gift of his,” Ceroni said.

“My strongest memory of Carlo is of a cheerful, lively boy. He was a typical boy his age, with a great zest for life and many dreams,” she said.

After graduating from the Tommaseo Institute, Carlo entered the Jesuit-run Leo XIII Institute in Milan. There, his faith stood out even more. “Carlo used to go to the chapel in the morning before entering the classroom and during breaks and would stop to pray. Nobody else did that,” said Father Roberto Gazzaniga, the school’s chaplain.

Classmates who testified in Carlo’s cause for canonization described him as respectful but unafraid to voice his convictions — on the Eucharist, baptism, pro-life issues, and the teachings of the Church. He also helped peers with homework, especially when computers were involved.

Carlo “never concealed his choice of faith,” Gazzaniga said. “Even in conversations and discussions with his classmates, he was respectful of the positions of others but without renouncing the clear vision of the principles that inspired his Christian life.”

The chaplain described Carlo as having had a “a transparent and joyous interior life that united love for God and people in a joyful and true harmony.”

“One could point to him and say: Here is a happy and authentic young man and Christian,” he said.

Unlike many at the private Jesuit school, Carlo paid little attention to what was trendy or popular. When his mother bought him new sneakers, he asked her to return them so they could give the money to the poor instead.

Acutis also asked a cloistered religious order to join him in praying for his high school classmates who partied in clubs and used drugs and spoke to his friends about the importance of chastity.

Carlo’s high school years were cut short when he was diagnosed with leukemia at age 15. He died in October 2006, just as his second year of studies was beginning, offering up his suffering from cancer for the pope and the good of the Catholic Church.

Sister Monica remembered vividly the last time she saw him a few weeks before he died. “We met right in front of the parish church,” she said. “We were going in and he was coming out of the church … He was happy to be back at school. He said he wanted to focus on computer science. I will always remember him this way.”

She returned to the parish for Carlo’s funeral not long after. “Carlo’s funeral ceremony was extraordinary. There were a lot of people, also poor people,” Ceroni said.

Today, both Sister Monica and Sister Miranda tell Carlo’s story to inspire their young students in the same classrooms where he once studied. “Carlo is presented as a child who was a friend of Jesus and found joy, because Christianity is joy,” Moltedo said.

Veronica Giacometti from ACI Stampa, CNA’s Italian-language news partner, contributed to this report.