The apostle Peter was made of flesh and blood, just like the rest of us. Yet he wielded spiritual authority over the devil. He said to the lame man at the temple gate, "In the name of Jesus Christ of Nazareth rise up and walk" (Acts 3:6), and the man was healed. The religious leaders of the day recognized this power in Peter and asked him, "By what power, or by what name, have ye done this?" (4:7).
Nowhere does the Bible suggest that this same power isn't meant for us today. When did the Lord ever say to His Church, "I've helped you so far. Now you're on your own"? What kind of God would empower His people in the wilderness when they needed it—would empower Israel's kings, prophets like Elijah, the crowds at Pentecost—and then withhold it from his last-days Church, when we need it more than any generation?
According to Scripture, Satan's power has increased in our day: "The devil is come down unto you, having great wrath, because he knoweth that he hath but a short time" (Revelation 12:12). Why would God permit Satan to attack a weak, powerless church that has no defense? His people have never lost access to His divine power.
Unfortunately, a number of Christians have a skewed idea of spiritual authority. This is especially true in charismatic circles. I know of a series of "power" conventions, where preachers lay hands on people to endow them with an anointing of spiritual authority. Yet, when the recipients return home, their efforts against the devil still fail miserably. They end up asking the same question the disciples asked Jesus: "Why couldn't we cast out these spirits?" You can't obtain supernatural power simply by having someone lay hands on you. It isn't a gift, it's a way of life, of walking with Jesus. And not everyone who asks for such authority will suddenly be changed into a spiritual powerhouse. The fact is, God entrusts His divine authority only to what Peter calls the "hidden man of the heart, in that which is not corruptible" (1 Peter 3:4).