Jesus had just spoken about relationships before He gave this parable of delivering ourselves from the judge. The warning is clear that we should do everything within our power to avoid strife (Romans 12:18). The consequences of failing to settle the differences are more than just physical prison or punishment.

Strife can produce spiritual and emotional prisons. James 3:16 says, "where envying and strife is, there is confusion and every evil work." Depressions, fears, loneliness, bitterness, sicknesses, financial problems, and many other things can become prisons from which we will not be delivered until we reconcile.

The dictionary states that to reconcile means "to re-establish friendship between; to settle or resolve, as a dispute" (American Heritage). The key to reconciliation is effectively dealing with the enmity, ill will, hatred, or hostility that has caused the dispute. 

There are several approaches to reconciliation that may be used. If we've offended someone by an unkind word that we've spoken, we can apologize. If we owe money to someone, we can pay the debt. If we've done something to someone we can make the necessary restitution. But in every case, reconciliation lies in dealing effectively with the root cause of the enmity.

The enmity between man and God was sin. God took the initiative to remove this barrier through Jesus Christ,  leaving Him and man as friends once again. 
Thank be to God for His great love!