Question: "How can I let the words of my mouth and the meditation of my heart be pleasing to God (Psalm 19:14)?"
Answer: Psalm 19, a psalm written by King David around 1000 BC, begins with a beautiful explanation of general revelation—that revealing result creation has due to how God created it—and ends with a request that the meditations of David’s heart would be pleasing to God. Creation reveals the glory of God (Psalm 19:1), declares the works of His hands (Psalm 19:1), and does all of this without words (Psalm 19:3). The biblical God has created the universe and all that it contains in such a way that it constantly glorifies Him through events such as the sun rising and setting. As Romans 1 states, “Since what may be known about God is plain to them, because God has made it plain to them. For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that people are without excuse.”
God’s creative role rightfully gives Him all authority, as all things are His (Job 38—41). With this authority, God gave laws and instructions to His people in the Mosaic Covenant, which David references in Psalm 19:7–11. David describes the laws as perfect or complete, the legal notices as sure, the Lord’s instructions as right, the Lord’s commandments as pure, and the judgments as true, righteous, and desirable. As David describes these various aspects of the law of God, notice the synonymous nature of his concepts. Each is working through an aspect of the relationship David has with the law and with God.
David then makes two requests of God: 1) that God would forgive him of hidden faults, and 2) that God would keep him from sins coming from arrogance and pride. He then concludes with the request that the meditations of his heart and words of his mouth would be pleasing to the Lord. David seems to be making a final request regarding his previous claims. Essentially, he’s saying, “Please let those things I have previously meditated upon and stated in this psalm be pleasing to you, Lord.”
The idea of “meditating” in the Scriptures points to filling the mind with thoughts of something or someone. To empty the mind, as some might think of meditation, is not the biblical principle. For example, in Psalm 63, David parallels the idea of thinking and meditating (Psalm 63:6). What David presents in Psalm 19 is a desire for God to be pleased with David’s thinking and, in turn, his speaking.
Jesus also makes a connection between the words of the mouth and the meditation of the heart. He taught, “A good man brings good things out of the good stored up in his heart, and an evil man brings evil things out of the evil stored up in his heart. For the mouth speaks what the heart is full of” (Luke 6:45; cf. Matthew 12:34). In the same way, David connects the mouth and the heart. Our words and our thinking are related. Both should be pleasing to the Lord.
Paul mentions the idea of pleasing God multiple times in his writing. In Romans 12:2, Paul shows that the renewal of the mind is critical for personal transformation and the understanding of God’s will, which is good, well-pleasing, and perfect. He reiterates this idea in Colossians 1:9–10 as he prays that the Colossians would be filled with the knowledge of God’s will so that they could then do that which is pleasing to God. He also tells Timothy that the Scriptures are God-breathed and profitable, making the man of God equipped to do every good work (2 Timothy 3:16–17). These good works are what Christians were created anew in Christ to complete and are predestined by God (Ephesians 2:10). The mind must be filled with that which is pleasing to God so that the mouth, and other body parts required for action, can also do what is pleasing to God.
Like David states at the end of Psalm 19, we should desire for our thoughts or meditations to be pleasing to God. We can ensure pleasing thoughts by filling our minds with scriptural truth, and that will lead to words and actions that are also pleasing to Him.