the end of the devil

C.S. Lewis was right about the devil.  He said in Screwtape Letters that there are generally too approaches to the demonic.  One is to be overly obsessed with them.  The other is to act as if they don't exist.  Neither approach is reasonable.
The Bible is not objective about the work of Satan.  It is purely one-sided.  :-)  He is the enemy of God.

There are many places in the Bible where the Devil is mentioned. 

1 Chr. 21:1; Job 1:6–9, 12; 2:1–4, 6–7; Zech. 3:1–2; Matt. 4:10; 12:26; 16:23; Mark 1:13; 3:23, 26; 4:15; 8:33; Luke 10:18; 11:18; 13:16; 22:3, 31; John 13:27; Acts 5:3; 26:18; Rom. 16:20; 1 Cor. 5:5; 7:5; 2 Cor. 2:11; 11:14; 12:7; 1 Th. 2:18; 2 Th. 2:9; 1 Tim. 1:20; 5:15; Rev. 2:9, 13, 24; 3:9; 12:9; 20:2, 7

The reason for the post is to talk about his end.

There will be a day when the Devil will go away.  Death will be swallowed up in victory 
(1 Corinthians 15:50-58)

his end is inevitable.  his destruction is certain.  
9 And  the great dragon was thrown down,  that ancient serpent, who is called the devil and Satan,  the deceiver of the whole world— he was thrown down to the earth, and his angels were thrown down with him.  10 And I heard a loud voice in heaven, saying, “Now  the salvation and the power and the kingdom of our God and the authority of his Christ have come, for the accuser of our brothers  has been thrown down,  who accuses them day and night before our God.  11 And  they have conquered him by the blood of the Lamb and by the word of their testimony, for  they loved not their lives  even unto death. 

Praise God!