He became a famous preacher (more than 350 preserved sermons are believed to be authentic), and was noted for combating the Manichaean religion, to which he had formerly adhered.
Ia menjadi seorang pengkhotbah terkenal (lebih dari 350 catatan khotbahnya yang masih terlestarikan diyakini otentik), dan ia juga dikenal karena perlawanannya terhadap agama Manikeisme, yang pernah dianutnya.