[Sectarianism is] a narrowing down of the ground of acceptable Christian fellowship and cooperation due to a broadening of what is considered orthodox doctrine. It is therefore my (or my group's) refusing to allow for diversity in others and demanding conformity with all my views, as if my view (in full detail) alone had divine sanction. It is the notion that I, or my own specific group alone has a market on the truth, to the exclusion of others.
- Rex A. Koivisto, One Lord, One Faith: A Theology for Cross-Denominational Renewal (Wheaton, IL: BridgePoint, 1993), pp. 44-45