He was from the pagan Persian aristocracy, but came to faith in Christ and left his home for the Christian city of Edessa, where he was baptized. He later moved to Antioch, where he lived in prayer and asceticism a short distance from the city. He ate nothing but a small amount of bread until he was extremely old, when he added some greens to his diet. Though he knew very little Greek, he was empowered by the Holy Spirit to win many converts to Christ and to confound the learned Arian heretics who were disturbing the Church in Antioch.

When Aphrahat learned that the Arian Emperor Valens was persecuting Christ's Church, he moved to the city to support the true Faith. One day the Emperor himself met Aphrahat in the city square and asked him why he had left his solitude and come to Antioch. The Saint answered 'Tell me this: if I were a maiden at home in my secluded apartment and saw someone setting fire to my father's house, would you not advise me to put out the blaze as soon as possible? That is what I am doing now, because the Church, the heavenly Father's house, is burning down inthe fire that you have set!' One of the Emperor's attendants threatened Aphrahat with death for this impertinence; but the attendant himself later perished, drowned as he was heating water for the Emperor's bath. This made the Emperor afraid to persecute the holy one, who continued to preach the true Faith and to perform many miracles. He reposed in peace.