It is hard to overemphasize the emphasis placed on the fellowship of believers in the New Testament. Yes, the fellowship of believers does not eclipse the personal relationship of each believer with God, nor does it soar above the call to disciple the nations and serve the suffering, but it certainly shines with its own staggering brilliance on many pages of holy writ. In fact, the fellowship of believers is the community where we share the fruit of our personal fellowship with God and the team with which we work to reach the world for Christ.
One way the New Testament shows the importance of our fellowship with other believers is the many times it speaks of what believers should do, and not do, to one another. Taken together, these passages are called the "one another's". While each of these exhortations about how to treat fellow believers has its own message to bear, the overall point should not be overlooked: one must be together with other believers to fulfill them. The writers of the Scriptures have certainly been a blessing to me even though I never met them! They did not have me in mind personally when they wrote their prophecies, letters, poetry and histories, but they were sharing priceless treasures with the whole of God's people, including me. Still, as we briefly consider the "one anothers", it will be hard to imagine fulfilling them without having frequent opportunities to for face-to-face fellowship with other believers.
Jesus sought to encourage fellowship among His followers by attaching wonderful promises to such fellowship. In Matthew 16:18 Jesus promises, "You are Peter [a stone], and upon this rock [bedrock] I will build My Church [Assembly, Congregation, Meeting]; and the gates [authority, power] Hades will not over-power it." Jesus compares the community of His followers to a building. Peter has just confessed that Jesus is the Messiah and Jesus says that upon this bedrock truth He would build His Church, composed of stones like Peter. To this fellowship Jesus promises victory over Satan. Then, in Matthew 18:15-18, Jesus promises to His Church that they shall have power to bind and loose on earth. This means that they have a responsibility and authority to exercise a faithful discipline over one another and to decide together what shall be the rules of their community. Of course, these should be in line with what God has already ordained in heaven and expressed through Scripture.
In verse 19, Jesus goes on to attach a special promise to group prayer: "if two of you agree on earth about anything they may ask, it shall be done for them by My Father who is in heaven." The "two" is not a limit on the number who should agree together in prayer. It is simply Jesus' way of saying that if there are even as few as two believers who live near enough to gather together for prayer, they should do so. Finally, inverse 20, Jesus promises that where "two or three" are gathered together in His name, He would be there, "in their midst." So, the Church Jesus said He would build must get together. They must gather to gather together for discipline, decision-making, prayer and worship. The very word we translate as "church" means "an assembly", the meeting of a special group of people dedicated to a specific purpose.
Now, let's get back to the "one anothers", the things we really can't do unless we do get together, whether in twos or threes or in larger groups. In John 13:5-17 we have the account of how Jesus washed His disciples' feet. After completing that menial task He said to them, "If I then, your Lord and the Teacher, washed your feet, you also ought to wash one another's feet; for I gave you an example that you also should do as I did to you." (verses 14-15) In other words, we are to help each other wash off the dust of our daily interaction with a sinful, fallen world. As Jesus said earlier, "He who has bathed needs only to wash his feet, but is completely clean; and you are clean, but not all of you." Here, He was referring to Judas who, because He had not truly believed in Jesus, had not been cleansed of his sins and would die in them. Still, even if we have been truly converted to Christ, we still need the daily cleansing from the sin that still clings to us so long as we are in this world. This, we can help each other to do as we fulfill the other "one anothers".
What are these other "one anothers"? We are commanded to "give preference to one another above yourselves." (Romans 12:10) This is a hard one, especially if we believe that our own needs are greater than those of others in the church; but if we are all, or most of us, doing this, no one's needs are overlooked. We are also enjoined "Be of the same mind toward one another…". (verse 16; see also 1 Corinthians 1:10) The more we each agree with God, the more of one mind we will be! This requires not only that we individually seek to know His will but also together as we meet to decide how to fulfill our part in the mission of Christ.
Some "one anothers" include prohibitions (see James 4:11; 5:9), such as this one: "Let us not judge one another anymore…" (14:13) Jesus forbids us to judge others (Matthew 7:1). This does not mean we are never to regard someone as being in the wrong but rather that we love them as ourselves and see ourselves as likewise subject to error and in no way their judge. (See Galatians 6:1) In the same vein, we are told to "Accept one another, just as Christ also accepted us to the glory of God." (Romans 15:7) When we think of what God has to forgive or overlook in us to accept us, it will make it easier for us to accept one another in our still imperfect conditions.
As this article must come to a close shortly, I will quickly reference the rest of the "one anothers", reminding you that all of them require we know and relate to other believers on a frequent and regular basis. We are to: "admonish one another" (Romans 15:14), "Greet one another with a holy kiss" (or hug or handshake - Romans 16:16 and several other verses ; you look them up), "Encourage one another" (2 Corinthians 13:11; 1 Thessalonians 5:11; Hebrews 3:13; 10:25), "Serve one another, humbly in love" (Galatians 5:13), "Bear one another's burdens" (Galatians 6:2), Speak "to one another in psalms, hymns and spiritual songs" (Ephesians 5:19), "Submit to one another" (5:21), "Regard one another as more important than yourselves" (Philippians 2:3), Bear with one another and forgive each other (Colossians 3:13), Teach and admonish one another (3:16), "Be hospitable to one another without complaint" (1 Peter 4:9), "clothe" ourselves "with humility toward one another" (5:5), "have fellowship with one another" in the light (1 John 1:7), gather together to "stimulate one another to love and good deeds" (Hebrews 10:23-25) In short, we are to "love one another" (John 13:35; Romans 13:8; 1 Thessalonians 4:9; 2 Thessalonians 1:3; 1 Peter 1:22; 1 John 3:11; 4:7, 11-12; 2 John 1:5).