St. Athanasius

As bishop of Alexandria, Athanasius knew that he had to protect his flock from the heresies of the Arians, who believed that Jesus was not truly God. He was hated and derided for adhering to the teachings of the Church and was even accused of crimes he had never committed. He was exiled from his city many times.
Athanasius never stopped teaching the truth, and eventually he was able to remain in Alexandria.