The Spirit of God wants each of you to capture any demonic strongholds that hold you captive
and strengthen the stronghold of the Holy Spirit in you.

2 Corinthians 10:4-5 says:

For the weapons of our warfare are not carnal, but mighty through God
to the pulling down of strongholds; casting down imaginations, and every high thing
that exalts itself against the knowledge of God, and bringing into captivity
every thought to the obedience to Messiah.
What is a stronghold? Why are strongholds important in literal warfare?
A stronghold is a defensive structure:
Psalms 9:9 The LORD is a refuge for the oppressed, a stronghold in times of trouble.
misgav; properly, a cliff (or other lofty or inaccessible place);
figuratively, a refuge:--defense, high fort (tower), refuge.