But the strongest argument I know regarding the biblical nature of church membership is probably the most obvious. What are the duties of elders? We can find their qualifications listed by Paul in writing to Timothy and Titus (1 Timothy 3:1-7, Titus 1:5-11)and from these glean much about their duties. And we have the plain statement of Peter,
Therefore, I exhort the elders among you, as your fellow elder and witness of the sufferings of Christ, and a partaker also of the glory that is to be revealed, 2 shepherd the flock of God among you, exercising oversight not under compulsion, but voluntarily, according to the will of God; and not for sordid gain, but with eagerness; 3 nor yet as lording it over those allotted to your charge, but proving to be examples to the flock (1 Peter 5:1-3).
The argument is simple: shepherds must know their sheep to be able to fulfill their duties as shepherds. Its just that simple. You cannot shepherd the flock of God when you havent a clue who the flock of God is. Every good shepherd knows his sheep. Only the hireling does not know the identity of the members of the flock. And, of course, the relationship is mutual. The sheep know their shepherd. They will not listen to anothers voice because they have been with the one shepherd so long they know his voice over against any pretenders or strangers. Such involves a relationship over time, just as the Christian elder is not to be a hireling, some young gunbrought in from outside, but should be one who ideally fulfills the commandment of Paul, The things which you have heard from me in the presence of many witnesses, entrust these to faithful men who will be able to teach others also (2 Timothy 2:2). The gospel is something that is precious, and you entrust it to the next generation. But it is the elders who make this decision, as they have to decide just who is truly faithfuland who has the ability to teach others. All of this requires community, exposure, contact, once again demonstrating that the shepherd must have direct knowledge of the identity, personally, of the sheep who have been entrusted to his care.
Further, Peter speaks of exercising oversight. While we may discuss the exact nature of what this means (and allow for differences given culture and geography and the like) one thing is for certain: it cannot be done without a relationship of some kind that involves real life. Obviously, this involved teaching and exhortation and discipline on the part of the elder. He is to be an example. You cannot be an example from a distance. You cannot be an example through a television screen or through the pages of a book. Modeling Christian maturity takes contact, exposure, and a reciprocal relationship that involves at least some kind of personal, communal, corporate context. All of this proves that despite the lack of the specific term membership rolls(something that would have been pretty dangerous at that point in time anyway), the activities of the elders and the form of the church itself requiresone to see the necessity of commitment to a particular fellowship identifiable by a particular group of elders. And if these texts were not enough, surely this command to all obedient Christians should be:
Obey your leaders and submit to them, for they keep watch over your souls as those who will give an account. Let them do this with joy and not with grief, for this would be unprofitable for you (Hebrews 13:17).
Here the Christian duty of obedience and submission, coupled with a need to make this work on the part of the elders of the congregation one of joy rather than grief, is enjoined upon all. This is not a command to servility, nor does it grant to Christian leaders despotic powers. But it does require believers to know who their leaders are. It is empty to say, “Jesus is my leader!” for the writer to the Hebrews did not say your “Leader” but your “leaders,” plural, and he would distinguish between them and the Great Shepherd only a few lines later (13:20). Nor does it do to claim to be in obedience and submission to men who do not see your face but once or twice a year. How can they give an account when they have no meaningful knowledge of your life, your Christian experience, your growth in godliness? How can they do so when you never attend upon their teaching or encounter them in the congregation?