ANSWER: The basic definition of Christian fellowship is that it is the act of meeting with those who are converted and who possess the same general beliefs. It is the sharing of knowledge and the trials and triumphs of life among those who are called and chosen of God. Such regular fellowship meetings are an essential element in a believer's spiritual growth and development.
The World English Dictionary defines fellowship as the act of people sharing activities, goals, interests, duties, trials, troubles and alike with one another in a group. Strong's Exhaustive Concordance of the Bible has six different definitions for this word.
Several basic elements to fellowship need to exist for it to be successful. The first is that those who meet together should have things in common like beliefs (Acts 2:42), work (Nehemiah 4:1 - 23), faith (1Samuel 20:30 - 42), need (2Corinthians 8:1 - 15) and what they struggle against (Daniel 3:16 - 30). Other areas of commonality necessary for fellowship include a common purpose (see Psalms 133:1), conviction (see 1Peter 3:8), and hope (Ephesians 4:4).
Another foundation in order to productively get together is in what is shared. Believers should share in the responsibility of helping others in the faith who may lack the essentials of life.
For to their power, I bear record, yea, and beyond their power they were willing of themselves; Praying us with much intreaty that we would receive the gift, and take upon us the fellowship of the ministering to the saints (2Corinthians 8:3 - 4, KJV).
They should also share in what it takes to preach the gospel to the world.
I (the Apostle Paul) thank my God on every remembrance of you, Always making supplication with joy in my every prayer for you all, For your fellowship in the gospel from the first day until now (Philippians 1:3 - 5, see also Galatians 2:9).
What should also shared is the power of God's spirit to bring people together (Philippians 2:1). Another element is that those who meet should all desire to walk in the light of God's word (1John 1:7). All believers should share in what is called the gospel mystery, "And that I might enlighten all as to what is the fellowship of the mystery that has been hidden from the ages in God . . ." (Ephesians 3:9, HBFV).
There are, of course, several other traits believers who fellowship together should share in but only a few are listed here to spur further study.
Fellowship, as a noun, or as action, demonstrates who we are. It allows us to interact with others who share common beliefs and sentiments. It allows us to recognize our own faults and gives us the opportunity to share in the spiritual growth of others. Moreover, as we have seen and as the Bible confirms, this is highly pleasing in God's sight. We should practice this outstanding spiritual trait whenever we can.