Albert Barnes Commentary 2 Corinthians 10:6

"and being in readiness to avenge all disobedience, when your obedience shall be made full." — 2 Corinthians 10:6 (ASV)

And having in a readiness, etc. I am ready to punish all disobedience, despite all that is said to the contrary.

Clothed as I am with this power and aiming to subdue all things to Christ—though the weapons of my warfare are not carnal, and though I am modest or timid (2 Corinthians 10:1) when I am with you—I am prepared to take any measures of severity required by my apostolic office to inflict deserved punishment on those who have violated the laws of Christ. The purpose of this is to address the objection of his enemies that he would not dare to carry out his threats.

When your obedience is fulfilled. Doddridge renders this: "Now your obedience is fulfilled, and the sounder part of your church restored to due order and submission." The idea seems to be that Paul was ready to inflict discipline once the church had shown a readiness to obey his laws and do its own duty. This delicately intimates that the reason discipline was not exercised sooner was the church's own lack of full promptness. Furthermore, it implies that action could not be taken against any offender as long as the church itself was not prepared to support Paul. The church was to show disapproval of the enemies of the Redeemer, demonstrate complete readiness to support the apostle, and unite with him in the effort to maintain the discipline of Christ's household.