"I am the vine," says Jesus, and proceeds to explain to His disciples that each of His followers is like so many branches growing from the one plant, nourished from the same root. A popular spin from that has been that vines don't know anything about fences, so there is no need for "established religion." That argument goes on to say that since "wherever two or three are gathered" Christ is there, then that is all there really is to "Church."
This sounds great for its simplicity, but then there are two meanings for the word, "Simple," aren't there? Taking the second idea first, if "wherever two or three are gathered" is the Church then haven't we traded the vine for a scattering of mushrooms? A vine is not so many bits of green here and there, with no relationship except with the root, or a gathering of green bits from here and there to form a vine. The root produces the vine, which grows branches which then grow tendrils and keep growing. We could go a lot farther into this picture, but the main point for today is that we are all connected (established) in Christ as so many parts of a living structure, supplying each other with that
grace which we ourselves are supplied by others. This brings in the ministries touched on in Ephesians 4 as well as Romans 12, &c.
As for the fences, the interesting part of that is a question: When have you seen a grape vine growing without some structure on which to climb? If we see such a thing, it is always a young vine, and without much fruit. A big, healthy, productive vine is a tended vine with a good trellis to support its branches. The vine Jesus was talking about was such a vine, with the Father Himself as the Vinedresser. Why would we want to paint ourselves as a wild vine, crawling through the weeds and thorns if God wants to prune and protect us?
In history, we started off with "established religion" as the Apostles and prophets, evangelists, and pastors labored together to nourish a single vine which withstood persecutions, heresies, and plagues for about a thousand years before suffering the first division (between the two ranking bishops, over what may yet be shown to have come primarIly of a language difference), and half another millennium before further divisions occurred. It may be argued that in nearly every schism the group leaving the larger body did so with great reluctance, and labored to prove itself to be, essentially, still part of that historical progression that is the "established" Church.
Roll the clock ahead a bit farther, and let Scholasticism gain its full growth and birth Humanism and Rationalism (yes, this is a simplified story!), and we see the coming of "movements" as diverse as Seventh-Day Adventism, Theosophy, Mormonism, Darbyism, and the "Watchtower." The Christian "Establishment" now consists of thousands of separate groups, each telling the other, "I have no need of you," while millions of people wander off into the void to be "churches" unto themselves.
We could follow this thinking to say that all Christians should therefore be members of the Roman Catholic or Eastern Orthodox churches, or even that one must be be saved. Conditions as varied as human history and God's grace would say otherwise. Then, what?
First, just as the vine to which Jesus compares us needs a frame to protect it from animals and rot, and to hold it separate from the other plants, the Church needs to grow on the framework He has provided us. Like it can be said that a vine has "generations" of growth from season to season, the truth, the spiritual DNA which defines our makeup as Christians, has been passed on to us from Christ, through our faithful (spiritual) ancestors. To be sure, there has been some lost and added, and so the need to find the "standard" as close to the root as possible so we can have some assurance that we are not just tied in to the latest religious fad to hijack that holy Name.
As well, we need to see that the vine really is distinct: Like a specialty grape compared with the thorns and weeds that grow around it. Just like the whole vineyard belongs to the vinedresser, so the world in general belongs to God: But just like the vine is uniquely his, the reason for his building the vineyard, so the Church is God's peculiar possession, the object of His love and attention. To be His means to be holy: any other option is rebellion.
Do we end on a negative note? Not at all, because that holiness is not a "work of rightousness" that we have to perform, but a blessing He wants to give us, a miracle for Him to work in our lives. Just as salvation, the New Birth, enables us to love God from a redeemed heart, His plan is to cleanse and renew us so that we may live and grow in that love "without wrath and doubting." Is this not the best there is?