Take for example, a look at Genesis 3. Adam and Eve had never sinned, and had dominion over the entire earth; they had faith, and they had the POWER and the PROTECTION, and the AUTHORITY that goes with that job!
Genesis 1:28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: AND HAVE DOMINION over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
They had the dominion, and the POWER to defend the earth against all attackers. Christ was called the second Adam. Christ went through the same temptation, essentially, that Adam did.
Matthew 4:8-11 Again, the devil taketh him up into an exceeding high mountain, and sheweth him all the kingdoms of the world, and the glory of them; And saith unto him, All these things will I give thee, if thou wilt fall down and worship me. Then saith Jesus unto him, Get thee hence, Satan: for it is written, Thou shalt worship the Lord thy God, and him only shalt thou serve. Then the devil leaveth him, and, behold, angels came and ministered unto him.
Christ ordered the devil away. And the devil WENT! Why? Where did that power to order the devil away come from? Christ said He could do NOTHING by Himself, but His Father, HE did the works. Christ's access to this POWER, this dominion over the earth and everything and every devil in it, came though FAITH in His Father!
CHRIST took the same test Adam did, but Christ passed it! Adam on the other hand... well.... yeah. Adam didn't. Why? How did the devil defeat Adam, when he couldn't defeat the second Adam?
Remember, the Devil didn't just kill Adam and Eve – Oh, no, that would have been quite impossible! God simply would not have allowed it. No, Satan had to first undermine their DEFENSES by making them sin and thereby destroying their FAITH! THEN he could do with them what he wished! He TRIED to do that with Christ, but Christ would not be seduced by avarice or greed or lust, or even hunger! Adam on the other hand, WAS seduced by those things, and DID cave in, and allow his faith to be destroyed!
Genesis 3:1 Now the serpent was more subtil than any beast of the field which the LORD God had made. And he said unto the woman, Yea, hath God said, Ye shall not eat of every tree of the garden?
He started right in, not attacking them – because you CAN'T attack TRUE FAITH – but by DECEIVING them, and talking them into sinning! And as we all know, he succeeded in his task, and they both ate the forbidden fruit.
Genesis 3:7-10 And the eyes of them both were opened, and they knew that they were naked; and they sewed fig leaves together, and made themselves aprons. And they heard the voice of the LORD God walking in the garden in the cool of the day: and Adam and his wife hid themselves from the presence of the LORD God amongst the trees of the garden. And the LORD God called unto Adam, and said unto him, Where art thou? And he said, I heard thy voice in the garden, and I was afraid, because I was naked; and I hid myself.
And so they HID themselves because they were AFRAID OF GOD! They had LOST their faith, their confidence in God, and the ability to BOLDLY go before God's presence! And when they chose to disobey God and destroy their faith, they lost their shield, and became the servants of the Devil! And this theme has been repeated BILLIONS of times since this earth began, in the same way, and for the same REASON!
Ephesians 6:13,16 Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand. ... Above all, taking the shield of faith, wherewith ye shall be able to quench all the fiery darts of the wicked.
The shield is chosen to represent faith for a reason; because your FAITH IS your shield! The SHIELD OF FAITH possessed by Adam and Eve is what prevented Satan from killing them on the spot. That shield of faith is the ONLY thing standing between you and destruction!
1 Peter 5:8-9 Be sober, be vigilant; because your adversary the devil, as a roaring lion, walketh about, seeking whom he may devour: Whom resist stedfast in the faith, knowing that the same afflictions are accomplished in your brethren that are in the world.
That faith is an impenetrable bulwark between you and all harm, and cannot be attacked with a frontal assault! The shocking bottom line is, that Satan needs YOUR HELP to destroy you! Without your help, without your WILLINGNESS to disobey God and thereby destroy your faith, he has NO power to harm you!