Spiritual warfare is the Christian concept of taking a stand against preternatural evil forces. It is based on the belief in evil spirits which are able to intervene in human affairs. Various Christian groups have adopted practices to repel such forces, as based on their doctrine of Christian demonology. Prayer is a common form of spiritual warfare among Christians. Other practices may include exorcisms, laying-on of hands, fasting, or anointing with oil.
Jewish demonology escalated with the rise of Jewish pseudepigraphic writings of the 1st Century BCE, in particular with Enochic apocrypha.Jewish apocrypha initially influenced post-New Testament writings of the early fathers, which further defined Christian demonology. Thus followed literary works such as The Didache, The Shepherd of Hermas, Ignatius's epistle to the Ephesians, and Origen's Contra Celsum.
Mainstream Christianity typically acknowledge a belief in the reality (or ontological existence) of demons, fallen angels, the Devil in Christianity and Satan. In Christian evangelism, doctrines of demonology are influenced by interpretations of the New Testament, namely with the Gospels, in that dealing with spirits became a customary activity of Jesus' ministry. Mark states that "he traveled throughout Galilee, preaching in their synagogues and driving out demons" (Mark 1:39).