John Michael Gendek, 15, of Hatfield (Credit: Lansdale Catholic/Facebook)
15-year-old John Michael Gendek inspired a movement of hope and unity known as JG3, leaving a lasting mark on his school and community
The Lansdale Catholic community and beyond are mourning the loss of John Michael Gendek, a 15-year-old sophomore whose strength, faith, and kindness inspired thousands during his courageous battle with brain cancer.
John passed away peacefully at home in Hatfield on Friday, surrounded by his loving family — parents Thomas and Lisa Gendek, brother Thomas, and sister Ashley — after a 13-month fight with medulloblastoma, a rare and aggressive brain tumor. His passing leaves a deep ache across Montgomery County, where his story became one of faith, perseverance, and unity.
(Credit: Lansdale Catholic/Facebook)
#JG3 (Credit: Lansdale Catholic/Facebook)A year of courage and community
Just days into his freshman year at Lansdale Catholic in September 2024, John was diagnosed after emergency surgery revealed multiple brain masses. Over the next year, he endured 30 rounds of proton radiation and six months of chemotherapy, never losing his quiet strength or gentle smile.
Throughout his treatment, John’s community rallied behind him with bracelets, shirts, and social media posts marked JG3 — a tribute to the #3 he proudly wore on the baseball field. From Lansdale Catholic to Mater Dei, from North Penn teams to local travel clubs, players wore his number on their wrists and sleeves in solidarity. “JG3” became more than a symbol — it was a message of hope and resilience.
In May, when John was released from the Children’s Hospital of Philadelphia after nine months, neighbors lined his Hatfield street in Phillies jerseys, waving signs and flags to welcome him home. His courage and faith continued to touch countless lives.
(Credit: John Earley)A life rooted in faith and love
This past September, one year after his diagnosis, John was granted a wish to visit The Vatican with his family — a trip that coincided with the canonization of Saint Carlo Acutis, the first millennial saint who also died at age 15. Lansdale Catholic staff later reflected on the powerful connection between the two faithful young men.
On Monday, the LC community gathered in the school gymnasium for a prayer service led by Bishop Chylinski, Father Chung of St. Maria Goretti, and Father Taglianetti, the school’s chaplain, to honor John’s life and comfort his classmates.
“John’s fight was courageous and filled with great strength and profound faith,” Lansdale Catholic said in a statement. “JG3 will remain imprinted on the hearts of so many in this community — representative of a heart that will remain gentle, innocent, and young forever.”
The school mourns Gendek on Monday (Credit: Lansdale Catholic/Facebook)
(Credit: Lansdale Catholic/Facebook)Remembering John
John’s obituary described him as “a special light with a gentle soul that touched all who knew him.” He loved baseball, fishing, firepit nights, and summers at the beach — always with his family by his side. His parents shared through a GoFundMe update earlier this month that they were grateful for every prayer and act of kindness that gave them “the gift of time together.”
John’s funeral Mass will be held Saturday at 11 a.m. at St. Maria Goretti Catholic Church, 1601 Derstine Road in Hatfield. Visitation begins at 9:45 a.m., and burial will follow at St. John Neumann Cemetery. Friends are invited to gather afterward at Mater Dei Catholic School to celebrate his life.
(Credit: Lansdale Catholic/Facebook)In lieu of flowers, the family requests donations to the Ronald McDonald House in Philadelphia, which supported them throughout John’s treatment.
Eternal rest grant unto John, O Lord, and let perpetual light shine upon him.
Read John’s full obituary and service details here.
A GoFundMe continues to raise money for the family, sitting at $90,740 of a $100,000 goal. Donate to the family here.
