Put on the Whole Armour of God

The Christian's spiritual armour is set forth in Ephesians 6:10-18. 
There are seven pieces of armour: (1) Loins girt about with truth, (2) The 
breastplate of righteousness, (3) Feet shod with the preparation of the gospel of 
peace, (4) The shield of faith, (5) The helmet of salvation, (6) The sword of the 
Spirit which is the word of God, and (7) Praying in the Spirit. Pay special attention 
to the "helmet of salvation" for the guarding of your thought life. Most demons 
seeking to re-enter assail the thoughts. Become watchful of any thoughts that 
could be considered negative; they are from the enemy. Separate their thoughts 
from your own. Refuse the thoughts they give you and replace them with positive 
spiritual thoughts.  Resist the devil at the first sign of his attack.

Philippians 4:8  Finally, brethren, whatsoever things are true, whatsoever things 
are honest, whatsoever things are just, whatsoever things are pure, whatsoever 
things are lovely, whatsoever things are of good report; if there be any virtue, and 
if there be any praise, think on (say) these things.

Confess Positively

Negative confessions characterize demonic influence. Positive confession is faith 
expressed. Confess what God's Word says. Any other confession will open the door 
for the enemy.  

Mark 11:23  For verily I say unto you, That whosoever shall SAY unto this mountain, 
Be thou removed, and be thou cast into the sea; and shall not doubt in his heart, 
but shall believe that those things which he SAITH shall come to pass; he shall 
have whatsoever he SAITH.

Excerpt from; 
Pigs in the Parlor by Frank and Ida Mae Hammond.  Chapter eight.