First Council of Constantinople

The First Council of Constantinople, held in 381 AD, was an important meeting of Christian leaders convened by Emperor Theodosius I. Its purpose was to address and clarify Christian beliefs, particularly the nature of the Holy Spirit and the relationship within the Trinity (Father, Son, and Holy Spirit). The council affirmed the Nicene Creed, expanding it to include distinct references to the Holy Spirit. It also condemned various heresies, especially Arianism, which denied the divinity of Jesus. This council helped shape the future of Christian doctrine and established orthodox beliefs that are still recognized by many Christian denominations today.