In the life of a believer there are two types of strongholds that can reside in our lives. Negative strongholds are wrong ways of thinking, reacting, responding and behaving that are contrary to God's truth and His ways. They are wrong mindsets and/or behaviors that have become entrenched in our lives. These types of strongholds are referred to in 2 Corinthians 10:4. All of us know what it is to have a negative stronghold whether it be fear, worry, anxiety, doubt, unbelief, anger, lying, gossip, immorality or a myriad of other things I could list. These harmful strongholds must be recognized for what they are, places within us where we are vulnerable to the wiles of the enemy, and they must be overthrown and destroyed by cooperating with God in the renewing of our mind. Rarely do we see these strongholds torn down in a miraculous moment. The majority of the time these strongholds are overthrown by concentrated cooperation with God over a long period of time by allowing His Word to do its supernatural washing, restoring and renewing work in our mind, for our thoughts become strongholds that influence our actions.
There is another stronghold that resides in the life of the born again believer, the dwelling place of God's Spirit within us. Colossians 2:10 tells us that we are filled with the Godhead Who is the Head of all rule and authority. This is what Paul is referring to in Ephesians 3:16, when He prays that we will be strengthened and reinforced with mighty power in our inner being. As wrong, ungodly strongholds are overcome and destroyed in our lives, the stronghold of our spirit where God's Spirit dwells needs to be strengthen and reinforced. While the Word is tearing down the negative it is simultaneously building up and strengthening the positive.
We give away which type of stronghold is in charge in our lives by our response to times of adversity. A person whose inner being is strong in the Lord and reinforced with His mighty power, will not be destroyed by outward circumstances. This is not to say that they won't mourn, grieve, ask God why, or have other normal emotional responses, but in the end their emotions won't have the last word. The truth that they've reinforced their mind, will and emotions with, that they've fortified their spirit with, will win out in the end. They will be a living example of unyielding and impenetrable inner strength, a living testament of a heart and mind ruled by God's peace.