John Owen (1616–1683) was an English theologian and Puritan church leader who is recognized as one of the most prominent and influential theologians in the 17th century. Having studied at the University of Oxford, Owen later held several high-profile positions including chaplain to Oliver Cromwell and vice-chancellor of the University of Oxford. Owen was a prolific writer, and his theological works deeply impacted the development of Reformed orthodox theology. He wrote extensively on various subjects within Christian doctrine, including the nature of God, the atonement, the Holy Spirit, and Christian living. He is perhaps best known for his emphasis on personal piety and for his writings on the doctrine of the Holy Spirit and the nature of communion with God. Owen's work has continued to be influential in Reformed and Calvinistic circles and is read widely by pastors, theologians, and laypeople interested in Puritan theology and history. Some of his most well-known works include "The Death of Death in the Death of Christ," which argues for the doctrine of particular redemption, and "The Mortification of Sin," where he details the believers' struggle against sin and the necessity of personal holiness.