On 19 March 2025, the Holy Synod of the Ukrainian Orthodox Church (UOC), led by Metropolitan Onufriy, made the decision to commemorate the 1700th anniversary of the First Ecumenical Council, as reported by the Information and Education Department of the UOC.
The celebrations are scheduled for 1 June 2025, which coincides with the Sunday of the Holy Fathers of the I Ecumenical Council.
The First Ecumenical Council took place in Nicaea (now in Turkey) in 325 and was a significant event in Christian history. During the Council, the Nicene Creed was established, outlining the key principles of Orthodox theology, and the Arian heresy was condemned. The Council played a crucial role in shaping the Church’s doctrinal teachings and promoting unity among Christians. Additionally, it set the precedent for determining the date of Easter celebrations across the entire Church.