– The previous Pope entrusted him with his secrets, so the all people loved him and presented him to become patriarch after the death of Pope Peter IV
– Pope Damian resisted the heresy of Peter III of Callinicum, Patriarch of Antioch, who denied the Holy Trinity
– Also resisted the followers of Melitius of Lycopolis (Modern day Asyut) who used to drink wine before officiating the liturgy