“…Once your obedience is complete” (2 Cor. 10:6, NIV)
There is a safety that comes when we get to the stage described in this verse: complete obedience.
It would be dangerous for God to entrust us with certain critical assignments before that. The outcome would be too uncertain. If He partnered with an unstable collaborator on a crucial assignment, the mission might abort and be destroyed. Too much is at stake. So he has to hold back meanwhile, testing us with smaller, less decisive assignments.