The spiritual principle revealed by this verse is that God will fulfill his purpose and can use any instrument He chooses to accomplish it. Whether that purpose is judgment or redemption, know this, He can accomplish it. He can use wounded men to do His work. The instrument is not important. His purpose is of paramount importance.
Availability is more important that use-ability.
Your ability is not what God must have. He desires your willingness. You are not disqualified from service because you have been hurt in the work of God. You are still useful to God, even if you have been defeated at one time. No matter how spiritual you get you are going to be disappointed with some things.