Answer
In order to understand the importance of Christian fellowship, we must first understand what Christian fellowship is and what it isn’t. The Greek words translated “fellowship” in the New Testament mean essentially a partnership to the mutual benefit of those involved. Christian fellowship, then, is the mutually beneficial relationship between Christians, who can’t have the identical relationship with those outside the faith.
The mystery and privilege that is Christian fellowship is that it exists because God has enabled it by His grace. Those who believe the gospel are united in the Spirit through Christ to the Father, and that unity is the basis of fellowship. This relationship is described by Jesus in His high-priestly prayer for His followers: “I have given them the glory that you gave me, that they may be one as we are one: I in them and you in me. May they be brought to complete unity to let the world know that you sent me and have loved them even as you have loved me” (John 17:23). The “complete unity” He refers to is the oneness that Christians experience in true fellowship, oneness with one another, with Christ and with the Father. Just as the Father is in Jesus, so is Jesus in us, and we have unity with one another because of the uniqueness of that relationship (1 John 1:3).
This relationship must be the basis of Christian fellowship. We can have friendships and relationships with unbelievers, but true Christian fellowship can only occur within the body of Christ. We are united to one another by common beliefs, purposes, and goals. Our hearts and minds are “other-worldly” because we follow Jesus Christ, who said that His kingdom is not of this world (John 18:36). We know that we are strangers in this world, and we long for the time when we will be in our true home, heaven.
The importance of true Christian fellowship is that it reinforces these things in our mind and helps us to focus on Christ and His desires and goals for us. As iron sharpens iron, in true Christian fellowship Christians sharpen one another’s faith and stir one another to exercise that faith in love and good works, all to God’s glory.