Saint Serafim Sarovsky.

Saint Seraphim of Sarov (Russian: Серафим Саровский) (1 August [O.S. 19 July] 1754 (or 1759) – 14 January [O.S. 2 January] 1833), born Prokhor Moshnin (Прохор Мошнин), is one of the most renowned Russian saints in the Eastern Orthodox Church. He is generally considered the greatest of the 19th-century startsy (elders). Seraphim extended the monastic teachings of contemplation, theoria and self-denial to the layperson. He taught that the purpose of the Christian life was to acquire the Holy Spirit. Perhaps his most popular quotation amongst Orthodox believers is “Acquire a peaceful spirit, and thousands around you will be saved.”
Seraphim was glorified (canonized) by the Russian Orthodox Church in 1903. Pope John Paul II referred to him as a saint.