The First Council of Nicaea (325 AD) stands as a watershed moment in the history of Christianity. Convened by Emperor Constantine, it sought to preserve the unity of the Church by addressing the Arian controversy, which questioned the divinity of the Son. Nicaea's Creed affirmed that the Son is ὁμοούσιος with the Father, safeguarding the truth of salvation and worship. Its doctrinal clarity not only defended the faith of the early Church but also laid the foundation for subsequent theological development. Seventeen centuries later, Nicaea continues to inspire fidelity, dialogue, and unity within the Body of Christ.