Matthew 7:16-18
You can recognize them by their fruit [i.e., by what their lives produce]. Do people harvest grapes from thorn bushes, or figs from thistle weeds?
Matthew 7:20
Therefore, you will recognize them [i.e., prophets] by their fruit [i.e., by what their lives produce].
Matthew 12:33-34
Either be a healthy tree and produce wholesome fruit, or be a diseased tree and produce rotten fruit, for [the quality of] a tree will be recognized by [the quality of] its fruit.
Matthew 15:19
For evil thoughts, murder, extramarital affairs, sexual immorality, stealing, perjury, slander --- [all these] come from a person's heart,