I regularly run into folks that believe themselves spiritually mature, but within a very short conversation, you are given reason to question that self-assessment. They complain about this, they bicker about that, and all under the umbrella of learned wisdom.
I will say this: We are not given experience and time as a Christian to become a calculated critic, but instead a seasoned servant.
The mission is not solely to assess what is wrong with the world or Christ's bride, the church. Any coward can do that. It seems to me that Jesus calls us to be a part of the solution.