According to the Orthodox Church in America:
The Holy Apostle Hermas was a bishop in Philippopolis, Thrace. He was a Greek, but he spent some time in Rome. The holy Apostle Paul greets him in the Epistle to the Romans (Rom 16:14). The Apostle Hermas endured much grief from the pagans for preaching the Gospel, but he died in peace.
According to Tradition, Saint Hermas is the author of The Shepherd, an instructive book based on revelations from angels.
According to the Prologue from Ohrid:
Hermas was one of the Seventy Apostles. He is mentioned in the Epistle of St. Paul to the Romans. Salute Asyncritus, Phlegon, Hermas, Patrobas, Hermes and the brethren which are with them (Romans 16:14). Hermas was a Greek by birth but lived in Rome for a long time. He was a bishop in Philipoupolis and ended his life as a martyr. He compiled a very instructive book called "The Shepherd" according to revelations from an angel of God. Hermas was a wealthy man, but, because of his sins and the sins of his sons, he fell into extreme poverty. Once while in prayer, a man appeared to him in white raiment with a staff in his hand and told him that he was an angel of repentance, who was sent to be with him until the end of his life. The angel gave him twelve commandments:
1. Believe in God;
2. Live in simplicity and innocence; do not speak evil; give alms to all who beg;
3. Love truth and avoid falsehood;
4. Preserve chastity in your thoughts;
5. Learn patience and generosity;
6. Know that a good and an evil spirit attend every man;
7. Fear God and fear not the devil;
8. Perform every good act, and refrain from every evil deed;
9. Pray to God from the depth of your soul with faith that your prayer will be fulfilled;
10. Guard against melancholy, the sister of doubt and anger;
11. Test true and false prophecies;
12. Guard against every evil desire.
Read the entire Shepherd of Hermas.