Who we really are on the inside will at some point be revealed outwardly by our words. According to Scripture, all of us make mistakes in what we say—it would take a “perfect” person to always bridle the tongue and thereby control the body as well (James 3:2-3). In fact, no one but Jesus is completely successful in this way. But to the degree that we walk closely with the Lord, the more our speech will be evidence that we follow Him.
In today’s passage, Jesus expresses this idea by means of a metaphor about good trees and bad trees. Making a distinction between the people who believe in Him and those who don’t, He classifies Christians as good trees, through whom the indwelling Holy Spirit is working to produce His good fruit. But men and women without Christ cannot generate any good fruit on their own. That’s because even mankind’s most virtuous deeds originate from the flesh and therefore are unclean to God (Isa. 64:6).
However, just because we are “good trees” doesn’t mean that good words will automatically come forth from our mouth. We need the Holy Spirit to help us use language that is edifying, gracious, wholesome, and true (Eph. 4:29-30). Let’s make it our ambition to abide in Jesus, allowing the Holy Spirit to steer our tongues and bring honor to Jesus Christ.
source: Charles Stanley