II Corinthians 10 -13 Paul returns to his concerns for the church and his relationship with them in these final chapters.  He defends his position as apostle and as the one that brought them the true Gospel.  He is concerned that they have listened to false teachers and given them the place that Paul should have, as Christ's ambassador to them.

There are a couple of key lessons that we need to think upon.

10:3-5 Here Paul teaches that "though we walk in the flesh, we do not war according to the flesh". 

There is a spiritual battle going on for the church.. and the only weapons that are effective are spiritual weapons.. " divinely powerful for the destruction of fortresses.... speculations... lofty things raised up against the knowledge of God."   Paul says, ".. we are taking every thought captive to the obedience of Christ."   The battle for believers.. is in our thoughts - intellect, perceptions, reasoning.
When we choose to bring our thoughts into submission.. in obedience to Christ.. we can be made complete.  We cannot judge ourselves or others by the outward appearance -  we must "test [ourselves] to see if [we ] are in the faith; examine [ourselves]!  (  13:5)

Paul teaches that, as Christ's apostle, he was appointed to:

" punish all disobedience" (10:6)
Build them up.. (10:8; 12:19; 13:9.10)
Work within the "sphere which God apportioned" to him. (10:14)
Not seek man's commendation.. but the Lord's ( 10:18)
"... spend and be expended for.. " their souls. ( 12:15)

Paul didn't want to be bold, strong, overbearing, super -wise, or burdensome to the church.  He wanted them to know that he loved them and was jealous for them. He wanted to see them be complete and mature in Christ.  He wanted them to rejoice, to live in peace, and to be filled with God's love.  He wanted them to walk in Truth and to be faithful.  He hoped that they would love and respect him and his associates as Christ's servants.

Seems a great purpose statement for every pastor or leader.

Father in heaven, let Your name be praised and hallowed in Your church everywhere.  Keep us from the false speculations and enable us to bring all our thoughts under submission, to obey Christ Jesus our Lord.  Strengthen Your servants, the pastors, teachers, elders, and leaders, in the knowledge and love of Christ, that they may build up the church in the sphere that You apportion to them.  Give strength when needed in their weaknesses.  Give wisdom from above.  Bless them with patience, love, and confidence in Christ, to the glory of His Name, in which we pray.  All glory we give to You, Father God, for You are so Worthy of our praise and worship.  Fill us with Your Spirit today we pray, Amen.