Finally, brothers and sisters, whatever is true, whatever is noble, whatever is right, whatever is pure, whatever is lovely, whatever is admirable—if anything is excellent or praiseworthy—think about such things. Set your minds on things above, not on earthly things.
God says you should bind all evil spirits out of your mind and put on God's Armor. Then pray a hedge of protection around yourself. God will do the rest.
Satan knows that your mind is still the same so he try's to attack your mind. The battle ground here on earth is for the control of your mind. The only weapon satan has is to attack you thru your thoughts. He tries to discourage you by telling you about all of your failures, sins, wrong choices and bad relationships you have had. He wants to take control of you by controlling your mind. He has no power so he uses deception and lies to try to deceive you.