Did St. Cyril of Alexandria accept original sin?

By CopticBot.ai (Coptic Space Inc.) · Last reviewed 2026-10-10

Yes, St. Cyril of Alexandria accepted and firmly taught the reality of the Fall and original sin (often referred to in the East as ancestral sin). However, his understanding must be interpreted according to the pure Alexandrian patristic framework, which rejects both the Pelagian heresy and the later Western concept of inherited legal guilt.

1. Rejection and Condemnation of Pelagianism

St. Cyril vehemently opposed the heresy of Pelagius and his disciple Celestius, who claimed that Adam’s sin affected only Adam, that mankind is born morally neutral, and that salvation could be achieved through unaided human willpower without divine grace.

At the Council of Ephesus (431 A.D.), presided over by St. Cyril, the Church formally condemned and anathematized Pelagianism and Celestius. St. Cyril affirmed that humanity suffers from a profound spiritual and physical catastrophe inherited from Adam, which made the Incarnation of God the Word an absolute necessity for salvation.

2. The Nature of Original Sin: Corruption and Mortality, Not Inherited Guilt

In his Commentary on Romans (particularly on Romans 5:12–19), St. Cyril explicitly addresses how Adam's sin passed to the human race.

St. Cyril explains that we do not inherit the personal moral guilt or legal culpability of Adam’s specific act. A person cannot be held morally guilty for a transgression committed before they existed. Instead, humanity inherits the consequences of Adam's transgression: corruption, mortality, and a diseased human nature.

St. Cyril illustrates this with the famous analogy of the root and the plant:

Just as a plant becomes damaged and sickly if its root is infected, so the entire human race—springing from Adam as its root—contracted the disease of mortality and corruption (phthora) when he fell.

Because Adam became mortal and subject to corruption, all who are born of his lineage are born into that same condition of mortality, spiritual weakness, and inclination toward sin.

3. The Need for the Incarnation and Holy Baptism

Because the disease of Adam was an ontological corruption of nature—resulting in death reigning over all—humanity was powerless to rescue itself.

• The First Adam vs. the Second Adam: St. Cyril taught that just as corruption entered through one man (Adam), incorruption and life were restored through the Second Adam, our Lord Jesus Christ (— Greek loanwords written in Coptic script). By uniting human nature to His divine nature, Christ healed the disease of human nature, conquered death by His Resurrection, and bestowed the Holy Spirit.
• Infant Baptism: St. Cyril strongly defended the baptism of infants. In the Orthodox understanding, infants are not baptized because they are personally guilty of Adam's sin, but because they are born into a fallen, mortal world subject to corruption and death. Baptism unites the child to the life-giving Body of Christ, bestows the Holy Spirit, cleanses inherited corruption, and grants eternal life.

Summary

St. Cyril accepted original sin as the inheritance of mortality, corruption, and a wounded nature resulting from Adam's disobedience. He rejected any notion that man is unaffected by Adam (Pelagianism), while preserving the true apostolic teaching that God does not hold descendants personally culpable for the ancestral transgression, but rather came in the flesh to deliver them from the bondage of death and corruption.