A Christian congregation is not a democracy - although it uses the democratic method of voting and parliamentary procedures. It is not a democracy, because if it were, than the consent of 51% would justify anything. Instead, the text of the Scripture stands above any vote.
A Christian congregation is also not an authoritarian structure. It is not governed by a pyramid-shaped, top-down hierarchy. Instead, we embrace the “priesthood of all believers” (Exodus 19:6, I Peter 2:9, Matthew 20:25, Mark 10:42, Luke 22:25).
The following three concepts might be presented as foundational for any notion of how to govern a Christian congregation: truth, stewardship, and love.
Truth is a governing principle, inasmuch as the text of the Scripture, and those same truths as reflected in the confessional documents of the church, are constant, invariable, and non-negotiable. The congregation must begin with the understanding that it is gathered around Jesus as the Living Word, and the text of the Scripture as the Written Word, and thus the idea of doctrine is an organizational cornerstone.
Stewardship is a governing principle, inasmuch as the congregation possesses its fellowship, not as property, but as a loan from God, and will be responsible to Him for how that fellowship is maintained.
Finally, love is a governing principle, inasmuch as all that is done must be done with an eye toward the benefit of others, and not the benefit of self - whether that self be an individual or collective.
There is much left unanswered here, and I do not claim to know all that is proper to governing a congregation. But perhaps I have discovered at least a little here.