God does not need you to defeat the devil. Jesus has already done it and given you the victory

1-John_5-4-3: For whatsoever is born of God overcometh the world: and this is the victory that overcometh the world, even our faith

Ephesians 6:11
Put onthe whole armor of God, that you may be able to stand againstthe wiles of the devil.

Ephesians_6-13: Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand

God does not need you to defeat the devil today. Jesus has already done it and given you the victory. (Colossians 2:15, Romans 8:37) Your part is to enforce the victory by simply standing your ground, which is victory ground. In other words, you “fight” from victory ground by standing