The Jews in Matthew 27:4, who had played on Judas' favor to get  his help in arresting Jesus, cared nothing for Judas. They had simply used him. The devil's crowd may flatter as long as they can use us, but we can be sure that when there is no longer anything in it for them, they will forsake us just as the chief priests did Judas.

The serpent didn't come to Eve in the garden threatening to bite her if she didn't eat of the forbidden fruit. He came with deception, presenting himself as being concerned for her welfare. Satan's greatest weapon is deceit.

Our success depends on how well we knows our opponent(s), so believers must not be ignorant of Satan's devices. 

Jesus stripped Satan of all his authority (Matthew 28:18). The power that Satan uses against us now, is deception. Those who gave other powers to him have already fallen prey to one of his lies. The devil deceives us and uses our own power and authority against us. The thing that makes deception so deadly is that those who are deceived don't know it. Once they realize they are deceived, they,re not deceived any more.

The best defense against the devil is to be so God-centered that you give no place to Satan. People who are very sensitive to the devil's presence usually are so at the expense of being sensitive to the Lord's presence. 

David said, "If I make my bed in hell, behold, thou art there" (Psalm 139:8). Anytime Satan's oppression is present, God's presence is there too (Hebrews 13:5). It's just a matter of where our focus is. Focusing on the devil is a trick of the devil. To win we must choose to focus on God instead.