The Mass is part of the diocesan celebrations of its 40th anniversary. Bishop Alan spoke of how 40 years ago Bishop Grant, who had a close connection with Cambridge and Ely, had petitioned the Pope to create the diocese of East Anglia and was also CAFOD's first chairman.
Bishop Alan said: "CAFOD had been created a few years earlier, after the Second Vatican Council from the response that the Catholic community had shown to the needs of others as they witnessed their plight around the world.
"Helping people in poverty around the world,church partners, and the wider Caritas International family is a heartfelt expression of our faith, carrying out those acts of mercy that we have been remembering over the last year: feeding the hungry, giving water to the thirsty, and welcoming the stranger.
"When the Diocese of East Anglia was created the Fast Days had become an established part of the Church’s calendar, in Lent and at Harvest, as they are today. Thank you, all of you, for the good work that you do for CAFOD in your parishes."
Stephen Matthews, CAFOD Community Participation Coordinator said: "CAFOD has always been a dear part of the work of this diocese, part of our mission to carry forward the work of Christ Himself in the world, helping people toward fulfilment, free from poverty and injustice. And so we pray, we fast, and we give generously to help our global neighbours."
In the afternoon, CAFOD partner, Sister Yvonne Mwila from Zambia, spoke about the work she is able to do thanks to the donations that people have given to the charity. She works with households in distress, caring for those who are orphaned, those with disabilities, and those who are living with HIV. Sister Yvonne and the Sisters of the Sacred Hearts of Jesus and Mary, care for these people, and they ask them "what would you like to do?' And so it was that Florence became a fisherwoman.
Florence lost her husband and son to HIV ' although she didn't know what it was ' and she thought she would be next. Through the care and treatment of the Sisters, she was nursed back to health.
When Florence said she wanted to be a fisherwoman the Sisters wondered how she would do it. But they gave her 500 tiny fish, tools and training to build a pond and farm fish. Florence became someone important. And in turn Florence has taught other people how they too can farm fish.
The day ended with Stations of the Cross, reflecting on the experiences of those who fall and thirst in Zambia, and so we accompany Jesus on his final journey toward the cross.
Lent Fast Day is on Friday March 10. There will be a collection in parishes for CAFOD's work on Sunday March 12. You can also donate online at www.cafod.org.uk or by calling 0303 303 3030.
Pictured top, Bishop Alan, Sister Yvonne Mwila, and CAFOD volunteers in the garden of St John's Cathedral and, above, Sister Yvonne speaks to volunteers.