Saint Isaac, also known as Isaac of Nineveh, was a 7th-century Christian monk and theologian. He is revered in both the Eastern Orthodox Church and the Catholic Church for his spiritual writings and teachings on asceticism and prayer. His works emphasize the importance of inner peace and the love of God. Isaac is often associated with the Syriac Christian tradition and is considered a key figure in the development of mystical theology. His feast day is celebrated on January 28 in the Eastern Orthodox Church and on July 30 in the Roman Catholic Church. His writings continue to inspire many in their spiritual journeys.