The Scriptures teach that the whole world is under the rule of a powerful, supernatural being called Satan, who is an absolute enemy of God, His creation, and His people. He is the ultimate deceiver. One a heavenly angel, Satan rebelled against God's rule in order to establish his own. In Genesis we saw how, through the serpent, he deceived Adam and Eve and usurped their God-given domain over the planet. He now hides in the ways we see the world: assumptions, values, political and religious systems. 1 John 5:19 says, "We know that we are children of God and that the world is under the control of the evil one." Satan is the "god of this world," ruling his counterfeit kingdom of darkness with a hierarchy of fallen angels.
Galatians 1:4 says Jesus "gave himself for our sins to rescue us from the present evil age, according to the will of our God and Father." The world-view of the Bible is characterized by warfare between God's Kingdom and Satan's. This is the backdrop of God's redemptive intent. In Genesis 3, God begins to reveal this to his people. Everything God does is determined by His plan to defeat Satan, overthrow his kingdom, and reestablish God's own effective rule over all creation. The whole Bible, therefore, is working toward this end.
Paul held this warfare world-view and warns us that the devil schemes against us: "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" (Ephesians 6:12).
It is of primary importance we understand God was, is, and will be the winner of this battle. The New Testament is very clear that the life, death, and resurrection of Jesus signaled a decisive victory by God over the kingdom of darkness:
When you were dead in your sins... God made you alive with Christ... And having disarmed the powers and authorities, he made a public spectacle of them, triumphing over them by the cross.
Colossians 2:13-15
God and Satan are not on equal footing. It's Creator versus created. Though Satan has power, it's nothing compared to the omnipotence of God. With a word, He could wipe out Satan and his army—and in Revelation 19, at the end of time, we see exactly this as Christ conquers all the demonic powers. But as we have previously seen in the Ephesians 6 passage, the war continues even though victory is assured. We do ourselves a disservice by not recognizing that standing for Jesus and His kingdom brings us into conflict with God's staunch enemy. Satan's attack means that we are all vulnerable to sickness, betrayal, financial meltdown, relational loss, emotional despair, and other hardships. One of the primary solutions Scripture dives to the problem of why bad things happen to good people is that we live in a war zone. There are casualties.
Be assured, God's promises still hold. When Satan and his forces toss our lives upside down, God's Spirit fights with us. When we feel attacked on all fronts, He fortifies our efforts with supernatural strength. And when we are down, wounded from a body blow, and can no longer fight, God fights the battle for us. In fact, He is always the one fighting the battle for us. We just need to stand firm and resist the enemy by faith in God's strength.
And He wins. Every. Single. Time.