From the beginning of the Bible (when God gives Adam four trees) to the end in Revelation when it talks about the trees that will line the river in heaven--trees that will bear 12 kinds of fruit-- the metaphor of fruit is compared to any number of things.

In Genesis 2:9, we read, "And out of the ground the Lord God made every tree to grow that is pleasant to the sight, and good for food; the tree of life...and the tree of knowledge of good and evil.  Four kinds of trees.  Pretty, tasty, life giving, and the one that was forbidden, the knowledge of good and evil.

In Revelation, the tree of life will bear 12 kinds of fruit for the healing of the nations.  So we see the analogy of the tree bearing fruit found in the Bible from the  beginning to the end.  But the fruit "concept" is also found all through out the Word of God.  Over and over again.

Galatians 5:22-23, "The fruit of the (indwelling) Spirit is love, joy, peace, patience, gentleness, goodness, faith, meekness, and self control..."  Also: Jesus said, "...by their fruit shall you know them..." in Matthew 7:16.  In other words, if you have God's spirit within you, it will show in your behavior.  The word "fruit" meaning behaviors.  And they identify you as a Christian.

One of my favorites is Psalm 1:3, "And he (God's child) shall be like a tree planted by the rivers of water, that brings forth fruit in their season; their leaf shall not wither, and whatsoever they do shall prosper."

You don't have to grunt and groan to produce fruit.  It is a natural occurrence of being God's tree--that is, you are a follower of Christ.  You just need to be planted in the right place.  Somewhere that you are regularly fed and watered.  Preferably by a river of water--which would be a place that God's word is discussed and taught.  The writer of Hebrews put it this way in 10:25: "Do not forsake the assembling of yourselves together as the manner of some is...but exhort one another..."

We need each other.  That's how we grow.  We help one another.  That's called a church.  And it is not relegated to a being a denomination.