What does the Bible teach about the relationship between the heart and speech?

In Scripture, the relationship between the heart and speech is notably illustrated in Matthew 12:34, where Jesus states, 'For out of the abundance of the heart the mouth speaks.' This emphasizes that the words we use are a reflection of our internal state. The heart is considered the seat of our thoughts, emotions, and desires; thus, a heart aligned with God produces speech that honors Him. Conversely, a heart corrupted by sin leads to destructive speech. This theological insight encourages believers to examine their hearts and seek renewal through Christ, nurturing a heart that fosters grace-filled communication and avoids harmful words.