Every church has at least few issues: some more than others. But what do you do when you’ve been called to a church where the very structure is non-biblical and possibly unbiblical?  Since you’ve been called by God, leaving is not an option. Ranting, though an immediate and temporary emotional release, is out of place in the Body and ineffective for the task of transformation.
I suggest five areas where we might place our energies.
Most of us have no doubt read the famous fruit of the Spirit passage in Galatians 5. You may have memorized it in Sunday school, vacation bible school, or a Navigators bible study. Some erroneously consider these to be lofty goals or activities to be added to the daily task list; they think the fruit is the focus. But fruit trees do not bear by focusing on the fruit; they bear by focusing on proper connection with sun and soil.
So it is with the fruit of the Spirit: we bear fruit as we focus on our connection with God by submitting to God’s rule and choosing daily (hourly?) to live by means of and in accordance with the Spirit. The blessings of submitting to God’s rule flow from the conscious choice to live by the Spirit and allow his life flow through ours. The works of earth-habituated flesh cannot do this.
How can we better focus on our connection with God? The spiritual disciplines play an important role, by training our responses in the ways of God. The disciplines are the means, not the end. It must not be our goal to be excellent at bible study, prayer, fasting, giving, and the like. Our goal ought to be worshipful, loving connection with the one true God. 
Our behavior is bounded by godly character. Knowing the truth about the biblical structure and function of the church is never an excuse to disrespect or demean our siblings: whether those who serve from the front or those who do not serve at all. We are to properly recognize those who serve before the whole Body, take responsibility for those who are weak (however they got that way), and do good to all in the Body and in the world.
So, what do we do? Assuming we’re working on our character by focusing on God, we decide to conform our behavior to his ways and we do so: one behavior, one moment, at a time.
Knowledge of error–whether our own or that of someone else–can consume our thoughts; we humans do tend to dwell. The problem is, we become like what we dwell upon. If we’re dwelling on problems and mis-alignments, we will begin to reflect those problems and mis-alignments in our attitudes and behaviors.
Paul’s instruction in Philippians 4 is the Word of God and a wise bit of advice: if our thoughts and habits shape us as persons, then we must be intentional about those thoughts and habits.
There are at least two ways to speak the truth: you can slam someone with it and feel better about yourself or you can speak it in love for the good of the other and the church. Only the second way leads to individual and corporate maturity and Christlikeness.
It is important to think clearly about true things and behave accordingly. The necessary relationship with our siblings in Christ is one of these true things. Informed, purposeful, and loving dialogue with others concerning the biblical structure and function of the church works toward transformation. Ranting, muttering, and complaining do not.
According to Ephesians 4, the Body grows itself, sourced fully in Christ, the Head. Pastoral staff do not grow the Body. Deacon or elder boards do not grow the Body. The Body grows the Body. This means you and I grow the Body.
One person or a small group of persons may not be able to change an entire local church. But a small group of persons can gather, focus on God, intentionalize their thoughts and habits, and learn to speak the truth in love. They can submit to Christ, live by the Spirit, and let God structure the group and its gatherings.
- We must not ask, “When will they do something?”
- We should rather ask, “When will you and I be something?”
 I assume both professional and lay persons are called to particular churches.
 Alan Knox raised this issue on Eric Carpenter’s post, My Church.