They overcome him by the blood of the Lamb

"They conquered him by the blood of the Lamb
and by the word of their testimony;
love for life did not deter them from death."  (Revelation 12: 11)

The Lamb of God has been slain.  I overcome Satan by confessing myself a worshiper of the slain Lamb.  Lamb of God who takes away the sins of the world, have mercy on me.  Lamb of God who takes away the sin of the world, grant me victory over the attacks of Satan.

What does it profit a man to win the whole world and lose his soul?  My life is nothing without the Lamb.  If I perish, I perish, if I live, I live.