St Matthew's, in Tarring Road, believes it is the first church in Worthing to install such a display, with 1,350 paper birds included in its Peace Dove installation.
The display was unveiled during the anniversary celebration weekend on Saturday and Sunday. Vicar Paul Taylor gave guided tours of the church, its youth lounge and grounds and the choir of Heene Primary School performed on Saturday afternoon, including a specially-written birthday song.
Sandra Hill said: "We created a Peace Dove installation especially for the celebration weekend for our 125th anniversary. It involves 1,350 paper doves with written prayers made by members of the congregation and community, hung throughout the centre aisle.
"It is similar to installations which have been on display around various cathedrals over the past few years but we believe we are the first church in Worthing to come up with such an installation."
The Peace Dove installation shows a flight of doves increasing in number from one single bird, representing how the church has grown into a vibrant and flourishing community.
Each dove is slightly different, reflecting the diversity of the congregation, and most contain a prayer for peace written by church members and the local community.
Sandra added: “We also held an art competition in collaboration with Heene Primary School and the top 70 finalists were on display, with the winners of each year group being announced by the mayor."
Worthing mayor Ibsha Choudhury presented prizes to the winners of the competition to design a birthday card for the church.
He said: "I want to congratulate the church on its 125th anniversary. It is very important for our diverse community that we promote diversity, mutual respect and, from a very early age, teach our children so they can learn about other religions. What brings us together is love and affection as a community."