On July 27, the Greek Orthodox Church commemorates the Feast Day of Agios Panteleimon. Feast Day of the Great Martyr and Healer, Agios Panteleimon The Great Martyr and Healer Agios Panteleimon was born in the city of Nicomedia into the family of the illustrious pagan Eustorgius, and he was named Pantoleon. His mother, Saint Evoula (Euboula) [+ March 30th] was a Christian.
She wanted to raise her son in the Christian Faith, but she died when the future martyr was just a young child. His father sent Pantoleon to a pagan school, after which the young man studied medicine at Nicomedia under the renowned physician Euphrosynos. Pantoleon came to the attention of the pagan Roman emperor Maximian (284-305 AD), who wished to appoint him as a royal physician when he finished schooling.
The Hieromartyrs Hermolaos, Hermippos, and Hermocrates, survivors of the massacre of 20,000 Christians in 303 AD (+ December 28th), lived secretly in Nicomedia then. Saint Hermolaos repeatedly saw Pantoleon when he came to the house where they were hiding. Once, the priest invited the youth to the house and spoke about the Christian Faith.
After this, Pantoleon visited Saint Hermolaos every day. One day the Saint found a dead child on the street. He had been bitten by a great snake still beside the child’s body.
Pantoleon began to pray to the Lord Jesus Christ to revive the dead child and to destroy the venomous reptile. He firmly resolved that if his prayers were fulfilled, he would follow Christ and receive Baptism. The child rose up alive, and the snake died before Pantoleon’s eyes.
After this miracle, Pantoleon was baptized by Saint Hermolaos with the name Panteleimon (meaning “all-merciful”). Speaking with Efstorgios, Saint Panteleimon prepared him to accept Christianity. When the father saw how his son healed a blind man by invoking Jesus Christ, he believed in Christ and was baptized by Saint Hermolaos and the man whose sight was restored.
Summary from source