In order to better understand why God gave us a mouth with a tongue in it, we are going to compare two passages of Scripture. We will see the revelation which is not given to us solely in one of the two passages.
In this case, the two passages that I have in mind are taken from the Old and New Testaments. In the New Testament, the Old Testament passage is quoted in a way that brings out a meaning that is not apparent in the Old Testament. The Old Testament passage is Psalm 16:8-9:
“I have set the LORD continually before me; because He is at my right hand, I will not be shaken. Therefore my heart is glad, and my glory rejoices; my flesh also will dwell securely.” (NAS)
Please focus on the phrase, "my glory rejoices." On the day of Pentecost, when the Spirit of God fell and the crowd gathered to know the reason, Peter preached his famous sermon. He referred to everything that happened in the life, the death, and the resurrection of Jesus. He quoted various passages from the Old Testament to prove that Jesus was indeed the Messiah and the Son of God. One of the passages he quoted was that one in Psalms 16:8-9. The quotation is found in Acts 2:25-26, where Peter says this:
“For David says of Him, ‘I was always beholding the Lord in my presence; for He is at my right hand, that I may not be shaken. Therefore my heart was glad and my tongue exulted; moreover my flesh also will abide in hope.’” (NAS)
Now, we put together those two key phrases: Psalm 16:9, "my glory rejoices"; and Acts 2:26, quoting the same passage, "my tongue exulted." Where David says in the Psalm "my glory"; Peter, inspired and interpreted by the Holy Spirit, says "my tongue." This tells us something very profound and important: our tongues are our glory. You might ask why. The answer is because the Creator gave each of us a tongue for one supreme purpose—to glorify Him. The only reason for a tongue is that with it you and I may glorify God. That is why our tongues become our glory. It is the member by which, above all others, we may glorify the Creator.
Dear Lord, thank You that I may glorify Your Name with my tongue, in praise and worship, in song, in testimony, in words of encouragement, grace, and hope. Thank You for Your Holy Spirit, Who will always guide and direct me to Christ, and His atoning sacrifice, to lead me in thanksgiving and worship. I praise You, Father, for Your precious Son. In His Name, Amen.