Fruit is used multiple times in the bible. What does it symbolize? 

Matthew 7: 15-20 states

False prophets can also be known by their fruit. We can confirm their fruit as found in 1 John 4: 1 where it says to test them to see if they are of God

Only good trees can produce good fruit, and if the work we perform endures, so too does the fruit. 1 Corinthians 3: 13-14

each one’s work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one’s work, of what sort it is. If anyone’s work which he has built on it endures, he will receive a reward.

As in any good fruit tree, if good fruit is produced from us, Jesus will prune the branches in our tree and more good fruit will be produced. John 15: 2

If good fruit is rewarded, then logically bad fruit must be punished.

Luke 3: 9. If good fruit is not produced, what good is the tree? Chopped down. Even if the tree has everything it needs [soil, water, sunlight] if no fruit is produced, it is as if it is dead. If we do not produce good fruit, we will be cut down. We are the trees, so we must always strive to serve God's word and bring others to Christ

So how do we yield good fruit? Our actions in this life. By leading others to Christ, being a good example, visiting the sick, encouraging others, growing in God's word, and obeying it are just some examples. 

By doing these, we are constantly pruned and can do more and more good becoming a beautiful, bountiful tree. The more we focus on God and his word, the more examples we may notice the more good we can do.

Thank you for reading.