How should I respond to spiritual attack? from Compelling Truth
Believers are told to wage war against sin (Romans 6) and against the forces of evil (Ephesians 6:10-18). Spiritual attack can be a result of direct demonic influence, or we may simply be experiencing the effects of living in a world that is cursed by sin and ruled by Satan. In either case, the approach is essentially the same: “be strong in the Lord and in the strength of his might” (Ephesians 6:10).
To be strong in the Lord and in His mighty power (as the NIV puts it) means to be aware of the Source of your strength, which is God Himself. Demons and Satan are formidable, frightening, and much more powerful than humans. But God fights for us, and within us, and they are no match for Him. Paul tells the Ephesians to put on the “whole armor of God,” which consists of the following pieces: the helmet of salvation, the shield of faith, the belt of truth, the breastplate of righteousness, the readiness given by the gospel of peace, and the sword of the Spirit, which is the word of God. All of these pieces of armor are things that illuminate God’s power, and our protection underneath that power. Our faith is given to us by God (Ephesians 2:8-9). Our righteousness and salvation are also gifts, resulting from that faith (Romans 3:21-26). The Holy Spirit indwells us because of that salvation (John 14:15-17; Ephesians 1:13-14), and He reveals truth and illuminates the meaning of the Word to us (John 17:17; John 14:25-26). Finally, because of all that we have been given, we are ready to bring the gospel of peace to others, so that they might have faith in God and be saved. This armor makes us very powerful, able to stand against spiritual attack. Paul also exhorts the Ephesians to pray at all times in the Spirit, to keep alert and persevere, and to pray for other believers, who are fellow soldiers (2 Timothy 2:3).