Recently I have been engaged in a conversation with several friends about the essential nature of the church and its implications. I want to continue that dialogue here and I hope you will help. In one of my early seminary classes we were asked to write a paper answering the question “What is the irreducible ecclesiological minimum?” That is the basically question I want to ask here; however, rather than tackle such a massive question in one post I want to divide it up into several smaller questions, that as a whole will answer the larger one.
I want you to post what you think those smaller questions should be. After this I will do another post where we can discuss the ordering of the questions as well as the validity of the questions. Then I will post each question individually and we will set out to answer them.
At this point I am not looking for anyone to justify the validity of their question I just want the questions themselves. Please read the other comments so that questions are not repeated. Please do not criticize questions posted by others. Feel free to post as many questions as you like, just make sure to leave a blank line between them so that they are easier to catalogue. Comments that do not conform to these guidelines will be deleted. I look forward to reading your comments and I hope this will be a beneficial dialogue. I will begin by posting the first question.
Missio Dei 
What does it mean for the church “to meet together” (Hebrews 10:24-25)?
My first question: “What does ‘irreducible ecclesiological minimum’ mean?”
Basically I am looking for the bare essentials. What things must be in place if we are to rightly consider an entity a church?
I did an exercise like this once with some people while going through Paul’s letters to Timothy & Titus.
My list:
1. A group of baptised believers.
2. Reading Scripture and praying while meeting together.
3. Observing proper roles (teachers / non-teachers, men & women roles).
4. Utilizing spiritual gifts.
5. Observing communion.
How big does the group have to be in order to be a church? The conclusion I reach is that it has to be big enough to allow for different spiritual gifts to be utilized. If those gifts aren’t emerging, then I have a hard time calling it a church.
It appears that maybe an elder doesn’t have to be appointed in order to call it a church (Titus 1:5), but elder appointment should at least be in expectation.
I think these are the bare minimum. I’ve observed the difficulty church planters have in classifying groups as “church” or not. For example, in Russian Baptist context laypeople are forbidden to baptise or conduct communion. So, you might have a group of believers in a village doing 1-4 above (or maybe they’re not baptised yet) who are just waiting for an elder from the city to come and baptise & have communion. Is that village group still a church? I would probably say “no” because they’re not doing 1-5. Once an elder is appointed among them, they would meet all criteria.
But if a group is doing 1-5 without elder appointment, I could call it a “church,” so long as the role of elders is considered important (maybe they’re all elders?) and his appointment is naturally forthcoming.