When we fellowship, an innate longing for God is partially met. Since man was made in the image and likeness of God, from time to time we experience the goodness of God from people around us. So God created man in His own image; in the image of God He created him; male and female He created them. (Genesis 1:27 NKJV)
In Colossians 1:27b, we read which is Christ in you, the hope of glory. (Colossians 1:27b NKJV). Often we may recall, getting a generous shower of hope from God when we fellowship with certain people.
Some people carry the presence of Christ within them in a tangible way. When we are with them, and interact with them, we are drawn to our savior Jesus Christ, and our joy and peace grow. A good reason for fellowship.
Father God sent Jesus into the World. In a similar manner, each one of us is sent into the world by Jesus. The verse in John 17:18 points to this. As You sent Me into the world, I also have sent them into the world. (John 17:18 NKJV)
Thus when we interact with people who have accepted Jesus Christ as Lord and Saviour, we interact with people who carry the presence of Jesus Christ within them. We experience the goodness of God through them.
When we meet and spend time with believers, we get much counsel and wisdom. Where there is no counsel, the people fall; But in the multitude of counselors there is safety. (Proverbs 11:14 NKJV). Another good reason to fellowship.
We are called to love our siblings, fellowship gives us the opportunity to practice this great commandment. Fellowship thus gives us the opportunity to grow in obedience to God’s Word. If someone says, “I love God,” and hates his brother, he is a liar; for he who does not love his brother whom he has seen, how can he love God whom he has not seen? Fellowship gives us a good opportunity to grow into loving God.
All these and more happen as we fellowship with fellow believers.