The definition of habit is:
1.an acquired behavior pattern regularly followed until it has become almost involuntary:
the habit of looking both ways before crossing the street.
2.customary practice or use: Daily bathing is an American habit.
3.a particular practice, custom, or usage: the habit of shaking hands.
4.a dominant or regular disposition or tendency; prevailing character or quality:
She has a habit of looking at the bright side of things.
5.addiction, especially to narcotics (often preceded by the).
6.mental character or disposition: a habit of mind.
7.characteristic bodily or physical condition.
It makes sense to reason strongholds are formed from habits.
Addictions come in many forms. Addiction to a substance, a person, or a relationship, can be harmful to the mind and soul.
This is why we should practice taking every thought into captivity.
Consistent thoughts can lead to unhealthy habits. While there are good habits to form, it is the unhealthy, unsafe, thoughts that lead to destruction.
What may have been helpful for a season, can be harmful if you do not release it when the season is over.
So, choose wisely what you allow your mind to entertain.