"I am He who lives, and was dead, and behold, I am alive forevermore. Amen. And I have the keys of Hades and Death." (Revelation 1:18)
Praise God that He sent Jesus to defeat Satan, so that we as Christians can also be warriors against demons and the devil himself. If Jesus had never died and gone into Hell to defeat Satan, we would not be able to cast out demons and heal people.
We must always remind Satan that he has already been defeated by Jesus, and because we are children of God, we have been bought by His blood and His dying and going down into "Hades", therefore Satan can't defeat us.