John of Kronstadt
His war experiences had a profound impact on Chichagov. He studied graduate-level medicine to provide better care for wounded soldiers, and pioneered research on the idea of treating wounds using substances derived from plants. In addition to medicine, he also became interested in theology. Chichagov undertook independent theological studies during which he decided to resign from military service and devote his life to the Church. Though his wife did not initially accept his decision, she was eventually convinced after speaking at length with John of Kronstadt.