What doctrine was addressed at the Council of Ephesus regarding Mary?

The Council of Ephesus, which took place in 431 AD, primarily addressed the doctrine of Mary as Theotokos, meaning "God-bearer" or "Mother of God." This title was significant as it affirmed the belief that Mary gave birth to Jesus Christ, who is acknowledged as both fully divine and fully human. The definition of Mary as Theotokos was defended against those who condemned the title, advocating for the understanding that since Jesus is God incarnate, Mary is rightly called the Mother of God.

This council was crucial in shaping the theological understanding of Christ’s nature and the significance of Mary within the Christian tradition. The affirmation of her title as Theotokos helped to clarify the relationship between the divine and human natures of Christ, countering various heretical viewpoints that denied the full divinity of Christ or diminished Mary's role.

The other options do not capture the main focus of the Council of Ephesus. While Mary's role as an intercessor and her assumption into heaven are doctrinal topics within Christianity, they were not the key issues addressed at this ecumenical council. Additionally, the title "The Foundation of the Church" is not a recognized designation for Mary in mainstream Christian theology, making it less relevant