1 John 1:3-7 that which we have seen and heard we declare to you, that you also may have fellowship with us; and truly our fellowship is with the Father and with His Son Jesus Christ. And these things we write to you that your joy may be full. This is the message which we have heard from Him and declare to you, that God is light and in Him is no darkness at all. If we say that we have fellowship with Him, and walk in darkness, we lie and do not practice the truth. But if we walk in the light as He is in the light, we have fellowship with one another, and the blood of Jesus Christ His Son cleanses us from all sin. NKJV

The word “fellowship” comes from the Greek word ‎koinonia, which is translated as partnership, participation, or (social) intercourse, or (pecuniary) benefaction. In the King James Version of the Bible it is translated as (to) communicate, communication, communion, contribution or distribution, or fellowship. (Strong’s Exhaustive Concordance).
John emphasizes the following points in this passage:
1. Fellowship with the Father and the Son is based on the fact of Jesus’ life, death, burial and resurrection. We must believe in all the Bible says about Jesus, and in confident faith obey his commands, we have communion with Christ.
2. When we have fellowship with God, we have joy, because we know that sins are forgiven, and we are right in the sight of God.
3. We cannot have fellowship with God and walk in sin or in darkness. It is interesting that one of the first things God created was light, and light is what characterizes a walk with God and His Son. We can see where we are going, and know that we are on the right path!
4. When we walk in the light, we have fellowship with God, with one another, and the promise of continual cleansing from sin!

The discerning Christian understands that we have fellowship on the basis of what Jesus did on the cross, and that we continue in that communion, or fellowship, on the basis of Jesus’ one time sacrifice. We are brothers and sisters in Christ, and we have the same Father and elder brother, Jesus!

Look at these passages that also talk about fellowship:

1 Corinthians 10:20-22 Rather, that the things which the Gentiles sacrifice they sacrifice to demons and not to God, and I do not want you to have fellowship with demons. You cannot drink the cup of the Lord and the cup of demons; you cannot partake of the Lord's table and of the table of demons. NKJV

2 Corinthians 6:14 Do not be unequally yoked together with unbelievers. For what fellowship has righteousness with lawlessness? And what communion has light with darkness? NKJV (see also Ephesians 5:11)

2 Corinthians 8:4 imploring us with much urgency that we would receive the gift and the fellowship of the ministering to the saints. NKJV

Ephesians 3:9 and to make all see what is the fellowship of the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ; NKJV

Philippians 1:5 for your fellowship in the gospel from the first day until now, NKJV

Philippians 2:1 Therefore if there is any consolation in Christ, if any comfort of love, if any fellowship of the Spirit, if any affection and mercy, NKJV

Philippians 3:10 that I may know Him and the power of His resurrection, and the fellowship of His sufferings, being conformed to His death, NKJV

One will also note from these passages that fellowship IS NOT ALL ABOUT EATING (note the fellowship of the mystery, in the gospel, and fellowship of his sufferings)! It is all about relationships with God and with our brethren. Sometimes we grow closer to one another around a table, where we eat and can share the things that are on our hearts (note the above definition on having “social intercourse”). But we can and should have fellowship in other ways as well – such as praying together, studying God’s Word together, and being there for one another when we need one another. When we limit fellowship to eating, and that is all, we grow in our waistlines, but not always in spirit of love and appreciation for God, His Word, or one another. In fact, sometimes we have seen disagreements happen at fellowship dinners that have ruined, not encouraged, the fellowship that God says we should have for one another.

We need to get beyond the fact that fellowship is always eating together. It is my fervent hope and prayer that we one day have a time of fellowship without eating, and spend that time feasting upon the Word of God and talking to one another and our Heavenly Father about the things that are really important – our spiritual needs, growth, and how we can encourage one another.

Thank God for fellowship.