Don't ever doubt that God is far, far stronger than Satan. Satan's power is limited; God's power is limitless. Satan's power is temporary; God's power is eternal. Satan's power is entirely evil; God's power is entirely good.
Furthermore, Satan is part of the creation—but God is the Creator. In fact, the Bible repeatedly calls God the "Sovereign Lord"—because that is what He is. It says, "Sovereign Lord ... you made the heaven and the earth and the sea, and everything in them" (Acts 4:24). Satan didn't make the world; God did—and God is still in control of it, because He is sovereign.
Yes, Satan has a certain measure of power, and we often see his power at work today. How else can we explain some of the terrible things that happen? Never forget that Satan has one goal: to block God's work wherever he can. To do this he will use every trick he can to deceive us and turn us away from Christ.
But someday Christ will return and destroy the devil's work. Satan is a defeated foe! Until that day, make it your goal to follow Christ. The Bible says, "Be self-controlled and alert. Your enemy the devil prowls around like a roaring lion looking for someone to devour" (1 Peter 5:8). Don't become his next victim!