Fellowship is crucial to the spiritual growth of believers. We tell them at the Ministry that if you're not in a good fellowship then you're on a sinking ship.

Hebrews 10:25 - We should not stop gathering together with other believers, as some of you are doing. Instead, we must continue to encourage each other even more as we see the day of the Lord coming.

We must remember that fellowship is God's design for growth and it is not just any gathering with any group but the gathering with God's group in obedience to His word.

The Greek word for fellowship is 'kay-nohn-ee-ah', which has the idea of common communion, a participating partnership where the jest of the conversation is about the Lord, Ministry opportunities, the sharing of God's Word and other spiritual issues... ect.

I’m sure many of you have heard about the camp fire illustration concerning fellowship where you have a blazing fire where all the logs are burning hot and bright but if you take one of the logs off the pile and set it off by itself it soon dies out. We need the body of Christ or we will drift- remember you are who you hang around with.
1 Corinthians 15:33