Contemporary Evangelical circles are particularly interested in the concept of spiritual warfare. Some Evangelicals believe that when someone is attacked by demons or fallen spirits, the targeted person can combat the attack by prayer, fasting, consulting with their spiritual advisers, and perhaps also by a process known as casting out demons.
A scriptural basis for the concept of spiritual warfare is found in the Epistle to the Ephesians, where Paul of Tarsus metaphorically arms the Christian with weapons and armor that recall those of a Roman centurion:
“ 10 Finally, be strong in the Lord and in his mighty power. 11 Put on the full armor of God so that you can take your stand against the devil's schemes. 12 For our struggle is not against flesh and blood, but against the rulers, against the authorities, against the powers of this dark world and against the spiritual forces of evil in the heavenly realms. 13 Therefore put on the full armor of God, so that when the day of evil comes, you may be able to stand your ground, and after you have done everything, to stand. 14 Stand firm then, with the belt of truth buckled around your waist, with the breastplate of righteousness in place, 15 and with your feet fitted with the readiness that comes from the gospel of peace. 16 In addition to all this, take up the shield of faith, with which you can extinguish all the flaming arrows of the evil one. 17 Take the helmet of salvation and the sword of the Spirit, which is the word of God. 18 And pray in the Spirit on all occasions with all kinds of prayers and requests. With this in mind, be alert and always keep on praying for all the saints. —Ephesians 6:10-18 ”