Since death and sin reign in this world and in us, we have no authority to battle Satan. However, Christ, who lives within believers, overcame sin and death and has the ultimate victory over Satan.
Christians do not have authority over Satan on their own, but Christ, who lives within believers, has ultimate authority over him. While Satan has power, it is incomparable to God's. Jesus demonstrated His power over Satan through His ministry, including casting out demons and healing the oppressed. Ultimately, Jesus’ victory over sin and death proved His authority over all things, and believers have Christ living in them, by which they have authority over Satan. However, the call is not to battle Satan but rather to resist him. Believers have authority to resist Satan’s temptations and live holy lives by the power of the Holy Spirit. Believers rely on God's Word and the armor of God to stand firm against sin, temptation, and Satan’s schemes. In the end, Satan will be defeated when Jesus casts him into the lake of fire, and believers can rest in the assurance that Jesus' authority protects them.
Satan's primary power is the power of influence that we give him in order to deceive us and keep us under the power of sin rather than under the power of God ( 2 Corinthians 11:3 ; 2 Thessalonians 2:8 - 12 ). In and of ourselves, we have no authority over Satan. This is why we see non-believers living under the power of Satan, unable to resist sin. However, when we believe in Jesus Christ, His power that lives within us fights on our behalf. We are able to say "no" to sin, live holy lives, and be protected by God. When Jesus was tempted by Satan, He responded by quoting the Word of God ( Matthew 4:1 - 11 ). Jesus is our example, so we, too, can defeat the Devil by the power of the Word of God ( Ephesians 6:17 ). In the end, because Jesus has all authority in heaven and E arth, we will have total victory over Satan ( Romans 16:20 ).When we believe in Jesus Christ ( John 3:16 ; Ephesians 2:8 - 9 ), we are indwelled with the Holy Spirit, and this is how we have power over the Devil. Galatians 2:20says, "I have been crucified with Christ. It is no longer I who live, but Christ who lives in me." The same God who created the universe lives within us. When we live in submission to God's Spirit, we have power over Satan, because the power of Christ operates in and through us. Satan cannot overcome believers in Christ, because Satan cannot defeat the Spirit of God that inhabits them.This does not mean Satan will not try to harm us. The Bible instructs us: "Be sober-minded; be watchful. Your adversary the devil prowls around like a roaring lion, seeking someone to devour" ( 1 Peter 5:8 ). Satan will attack and deceive; he will be seeking an inroad into our lives. This is why as Christians, we are to: "Put on the whole armor of God, that you may be able to stand against the schemes of the devil. For we do not wrestle against flesh and blood, but against the rulers, against the authorities, against the cosmic powers over this present darkness, against the spiritual forces of evil in the heavenly places" ( Ephesians 6:11 - 12 ). As Christians, while we may still struggle with evil and the temptation to sin, Satan will flee when we resist him in Jesus' name ( James 4:7 ; 1 John 4:4 ).