Summary: An apologia for belonging to your local congregaion.
“Those who received his word were baptized, and there were added that day about three thousand souls… And the Lord added to their number day by day those who were being saved.” 
In one of his sermons, Charles Spurgeon spoke of his intense desire to be a member of a local church. “I well remember how I joined the church after my conversion. I forced myself into it by telling the pastor, who was lax and slow, after I had called four or five times and could not see him, that I had done my duty, and if he did not see me for church membership, I would call a church meeting myself and tell them I believed in Christ and ask them if they would have me.” 
Clearly, this stalwart of the Faith held a high view of membership in the local congregation. However, the concept of church membership has fallen into woeful neglect among the churches of our Lord in this day. I am not certain when the transition occurred, but membership in the local church seems to be well nigh universally disregarded, if not actually disdained, today. Modern Christians seem to believe that the Faith of Christ the Lord involves believing only, and does not include belonging. However, believing assuredly leads to belonging, for the one who believes will love the church as much as does the Saviour who redeems it [see ACTS 20:28; EPHESIANS 5:25].
Church membership is not merely enrolment for the sake of having one’s name on a list, nor is it solely an issue of privilege. Outside of Canada and the United States, especially in nations where confessing faith in Christ the Lord may entail considerable cost, it is rare that one would find a Christian who remains unconnected to a local congregation. Being a believer is synonymous with being a member of a local church, both in the Word of God, in historical experience and in the experience of Christians outside of North America. However, in Canada, membership is too often associated with paying dues, performing meaningless rituals, abiding by silly rules and simply having one’s name on a roll that is seldom consulted. However, the New Testament presents quite a different picture of membership in the local congregation.
To be a Christian without holding membership in a congregation is akin to being a hockey player without a team. Perhaps you enjoy playing the game, but you really do not compete. Professing Christ without holding membership in a local congregation is somewhat like being a tuba player without a band. Though you play ever so well, it is only as the tuba lends its melodious bass in harmony with the entire band that the beauty of the instrument is truly witnessed. To be a Christian without holding membership in a local congregation is to be a sheep without a flock, exposed to danger. To be a Christian without accountability to a local congregation is to be an orphan without a family. 
In studying the New Testament, I observe that the writers frequently address or speak of a “church” and often refer to the “churches.” The word “church,” or the plural, “churches,” occurs 109 times in the ENGLISH STANDARD VERSION of the New Testament. In other versions of the Bible, the word “church” and its cognates occurs 110 times.  I leave it to you to find the extra occurrence. In six instances, the Greek term ekklesía occurs in the autographs though the word is not translated by the English term “church” in the ENGLISH STANDARD VERSION.
It is indisputable that the overwhelming number of occurrences of this word in the Greek text clearly speaks of a local congregation. This would have been the usual understanding for the first readers of the New Testament, even in the very few instances that we question what the writer may have meant. This point is sufficiently important to stress in order to gain an appreciation of the church in the view of early Christians.
Accordingly, it would be fair to say that the local congregation loomed large in the estimate of the writers of the New Testament. If we should discover that the early Christians valued church membership, we should see their practise as a model to emulate. If they treat membership as the expected practise of all who name the Name of Christ, we are obligated to adopt that practise in our own day.
In order to explore this issue more fully, I deliver this homily, based loosely upon ACTS 2:41, 47. In these two verses I note that Doctor Luke twice stresses addition to the number of the believers. I am quite certain that his language is not superfluous, but rather than he is carefully reporting what occurred with a view to providing a model for each church during the Age of Grace.