Paul tells us in Ephesians.......

Eph 6:12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.

So how do we fight this battle against spiritual wickedness? We fight it with the word of God. We read and study the Bible. Wanna see it in action? Just look at the temptation of Jesus.....

Mat 4:3 And when the tempter came to him, he said, If thou be the Son of God, command that these stones be made bread.
Mat 4:4 But he answered and said, It is written, Man shall not live by bread alone, but by every word that proceedeth out of the mouth of God.

Jesus used Deuteronomy 8:3 to ward of this attack.

Mat 4:5 Then the devil taketh him up into the holy city, and setteth him on a pinnacle of the temple,
Mat 4:6 And saith unto him, If thou be the Son of God, cast thyself down: for it is written, He shall give his angels charge concerning thee: and in their hands they shall bear thee up, lest at any time thou dash thy foot against a stone.
Mat 4:7 Jesus said unto him, It is written again, Thou shalt not tempt the Lord thy God.

Jesus used Deuteronomy 6:16 on this one...

Mat 4:8 Again, the devil taketh him up into an exceeding high mountain, and showeth him all the kingdoms of the world, and the glory of them;
Mat 4:9 And saith unto him, All these things will I give thee, if thou wilt fall down and worship me.
Mat 4:10 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.

And here it was Deuteronomy 6:13

We have got to know our Bible to ward off the attacks. Knowing Gods word keeps you armed and ready so satan can't get a foothold in your life. Knowing the word of God helps you spot the false teachings that are out there. Most of all reading and knowing the word of God gets you closer to God. Put on the whole armor of God......

The belt of Truth
The breastplate of Righteousness
The shoes of The Gospel
The shield of Faith
The helmet Salvation
And of course, the Sword which is your Bible

Gear up for the battle against satan, it's going on right now in your life. Paul tells us....

Eph 6:13 Wherefore take unto you the whole armor of God, that ye may be able to withstand in the evil day, and having done all, to stand.

So put on the armor and satan take your best shot!