Regardless of God's almighty power, He gives us "power" in our own lives. That power is through free will to make our own choices. Therefore, it is OUR choice whether or not we overcome evil with good. If we so choose to ask God for the strength to overcome evil in our lives, He will give us the strength to do so. Sure, evil can become powerful, but it will never defeat the power of God. If someone ends up in hell, it is from their choice to turn their back on God and not care or want to change it.