Parishioners packed inside St. Pascal Church, 3935 North Melvina Avenue, for a service led by George.
George, who went to St. Pascal School as a child, said it was "a wonderful feeling" to be able to kick-off the year-long centennial celebration where he was introduced to the faith.
"I always have a great sense of gratitude to this parish," George said afterwards. "It helped shape me in Christ and as a churchman, and it took care of my family for so many years."
And the event also marked a personal anniversary for George. He will mark his 50th year in the priesthood in December.
"This is kind of a kick-off for me too," George said with a laugh.
Reflecting on his career, the 74-year-old head of Chicago's Archdiocese who battled cancer for the second time earlier this year said the priesthood has allowed him to travel the world and interact with many people.
"You trust God in no matter what role in life you feel that he's called you, but the priesthood is truly a marvelous vocation," George said. "My life has been extraordinarily rich, and I'm grateful for that."
George said Pascal's parish had changed a bit since he was young but said the "spirit" remained the same. He said one change, which is common for most parishes in Chicago, is an increase in first-generation immigrants.
"When I was growing up, it was German, Polish, Irish, Italian...third-generation, four-generation kids, but now we're back to, in the diocese as a whole also, to taking care of first-generation again," he said. "And the parishes are open, and they're welcome."