The grapevine is a profilic plant: a single vine bears many grapes. In the Old Testament grapes symbolized Israel's fruitfulness in doing God's work on the earth. In the Passover meal, the fruit of the vine symbolized, God's goodness to His people.
Christ is the vine, & God is the husbandman who cares for the branches to make them fruitful. The branches are all who claim to be followers of Christ. The fruitful branches are true believers who by their living union with followers are as good as dead & will be cut off & cast aside.
Jesus makes a distinction between two kinds of pruning (1) separating & (2) cutting back branches. Fruitful branches are cut back to promote growth. God must sometimes discipline us to strength our character & faith. But branches that don't bear fruit are cut off at the trunk, because not only are they worthless, they often infect the rest of the tree.
Prayer, joy, & soul-winning are also fruit.
Abiding in Christ means (1) believing he is God's Son (2) receiving Him as Saviour (3) doing what God says (4) continuing in faith (5) & relating to the community of believers. Christ's body Jesus says to only live a truly good life is to stay close to him, like a branch attached to the vine. Apart from him our efforts are unfruitful.
When a vine bears "much fruit," God is glorified, for daily He sent the sunshine & rain to make the crops grow, & constantly be nurtured each tiny plant & prepared to blossomed. What a moment of glory for the Lord of the harvest when the harvest is brought into the barns, safe & ready for use! This farming picture shows how God is glorified when people come into a right relationship with him & begin to "bear much fruit" in their lives.
Joy comes from a consistent relationship with Jesus Christ. The joy of living with Jesus Christ daily keeps us levelheaded no matter how high or low our circumstances.
We are to love one another as Jesus loved us, & He loved us enough to give His life for us. Give all the love you can, & then try to give a little more.
Jesus made the first choice --- to love & to die for us; to offer us eternal life. We make the next choice --- to accept or reject His offer. Without His choice, we would have no choice.
Reference summary used from the Life Application Bible KJV, Tyndale Publishing House, Inc., Wheaton, IL