The Fruit of the Spirit perfectly illustrates the vicarious spirit of the cross. The tree bears fruit for the good and benefit of others, for those who come to it and partake of it. The fruit of the tree is yielded up for the good of others. It is a wonderful parallel we see here to help us better understand both the cross and the Fruit of the Spirit. He died for others.
Fruit is something produced that is plucked and benefits others.
A productive outgrowth of an inner life source. What Christ within produces as fruitful from without. The joy of seeking the welfare of others regardless of the cost or the consequences. Selfless sacrifice in behalf of others. It always sees what is ultimately best and good in the moral sense.