It means that if you make even the slightest concession with some people they will continue to take from you until it exceeds where things began.
The devil and his kingdom is the same way.
That’s what spiritual compromise does. It gives the enemy an inch of ground into your life and before you know it they have taken a whole lot more.
In this context the word “compromise” means a concession to something derogatory or prejudicial ( i.e. a compromise of principles).
2 Corinthians 10:3-6 (NKJV)
3 For though we walk in the flesh, we do not war according to the flesh. 4 For the weapons of our warfare are not carnal but mighty in God for pulling down strongholds, 5 casting down arguments and every high thing that exalts itself against the knowledge of God, bringing every thought into captivity to the obedience of Christ, 6 and being ready to punish all disobedience when your obedience is fulfilled.
Another versions, the NLT, shines a light that may be clearer to some of you.
2 Corinthians 10:6 (NLT)
6 And after you have become fully obedient, we will punish everyone who remains disobedient.
There can be no victory in any part of your life if there is spiritual compromise because it means you are being disobedient to His rules and guidelines for your life.
No matter what some teach – there are no such things as small sins. All sin is sin and gives the powers of darkness a place in your life. As long as you do that there will be problems, torment and confusion.
To gain victory in spiritual warfare you must take back ground given to the enemy.
So many people and churches wage warfare against powers and principalities when they cannot even wage a successful warfare in their own lives.
To win this war start by taking back the ground given the enemy in your life. Then seek direction in the areas of your marriage or family that the enemy has been given ground. Reclaim those two areas and you will see the sphere of spiritual influence increase exponentially outside of your small circle into the world around you.
Until you do that you are spiritual Don Quixote fighting windmills and losing ground!