Each tree is recognized by its own fruit. People do not pick figs from thornbushes, or grapes from briers.
“Judge a tree from its fruit, not from its leaves”
In the Old Testament law set aside the Israelites from all other nations and peoples. In many ways, the law, set them apart in behavior. One word to describe this would be the word “holy.” When Israel was healthy it viewed the law was viewed as a gift. When Israel viewed the law as only “behavior” they were always in decline.
Fast forwarding to the New Testament we see that the “law” or behavior was used to glorify self righteousness by the Pharisees and Sadducees.
In the analogy of a tree and its fruit behavior could be viewed as “leaves.” Leaves on a tree aren’t really that spectacular. The truth is, most trees have leaves.
However, fruit is a completely different thing. The following verses are the references for Jesus teaching on trees and their fruit.
An unhealthy tree can’t bear healthy fruit. A healthy tree can’t bear unhealthy fruit. The fruit and health of a tree are linked to the overflow of the heart. Behavior isn’t fruit.
The fruit that a Christian is to bear…the fruit that a church is to bear. What is that fruit.
I conjecture that we are to produce other disciples devoted to Jesus Christ.