That which we have seen and heard declare we unto you, that ye also may have fellowship with us: and truly our fellowship is with the Father, and with his Son, Jesus Christ.
I John 1:3
Through the writings of John in his first epistle, we can see his desire for believers to enjoy the unity that fellowship in the spirit of Christ can produce. Philosophy, methodology and personal ambition within the body of Christ will almost always be divisive, but true worship of the person of Christ will bring believers to a common point of focus and will draw our attention away from those things that would divide us.
John testified in the verses preceding this one, of what he had seen and heard as he experienced Christ. Fellowship with Christ should always cause us to reach out for fellowship with others. We can experience Christ through the revelation fo His written word and through the ministry of the Holy Spirit.
The doctrine of Christ becomes the central basis for fellowship with both God and other believers. If there is not agreement on the doctrine of Christ, there is no basis for the type of fellowship that is described here.
There is a progression of fellowship. We begin with our own fellowship with Christ. Then we relate what we have learned of Christ with other believers. This ultimately leads to simultaneous fellowship with Christ and believers. Anytime believers are together, focused upon Christ, this level of fellowship can take place, Matthew 18:20. This presence of God is via the indwelling Holy Spirit. As believers, our fellowship should always manifest the presence of God. The Greek word koinonia describes this fellowship as literally being communion with God.
Personal fellowship with other believers happens on three levels: 1) the idle, shallow chit-chat that characterizes so much of our discussion of the inconsequential. 2) An intermediate level where things of common interest are discussed. 3) A deeper level of fellowship that is based upon a discussion of the things of God. This is fellowship that is focused upon worshipping God through His Word. It is at this level that koinonia occurs. Sadly, many believers spend very little time at this level of fellowship. It seems that most of the time we are bogged down in the first two.
This fellowship is never negative. Interaction between believers that includes gossip, criticism, ungodliness, deceit, or immorality does not fit the biblical description of koinonia. If it is not koinonia, then Christ is not a part of it.
We should always remember that grace is the basis of our fellowship with the Father. The work that Jesus did on Calvary was to bring us to a place of unity with the Father. We should let that same grace of God extend through our hearts to others by the Holy Spirit.