Psalm 50 spells out the sin of the unclean use of the mouth and its consequences. Many in God’s house have taken His Word lightly on this matter
“Thou givest thy mouth to evil, and thy tongue frameth deceit. Thou sittest and speakest against thy brother; thou slanderest thine own mother’s son. . . . Thou thoughtest that I was altogether such an one as thyself; but I will reprove thee, and set them in order before thine eyes. . . . Whoso offereth praise glorifieth me: and to him that ordereth his conversation aright will I shew the salvation of God” (Psalm 50:19-23).
So, why don’t we fear and reverence God’s Word on this matter? Why do we so easily speak of others with vain words? Why do we continue to use words carelessly, with an uncontrolled tongue? This psalm tells us why: “Thou thoughtest that I was altogether such an one as thyself.”
Simply put, we make God out to be like ourselves. We bend His Word to reflect our own tendency to judge the outward person. And we ignore God’s ways of considering the hidden, deeper issues of a person’s heart.
Now the Lord is telling us here in Psalm 50, “I’m going to reprove you, because I want you to set this matter in order. You have to see your defilement the way I do: as wicked and evil, a serious danger to your soul.”
As a minister of the Lord, I want Christ’s life to flow out of my preaching. And as a husband, father and grandfather, I want it to flow out of me freely to my family. Therefore, the fountainhead of Christ’s life in me cannot be polluted. I cannot allow any poison in the spring, or any roadblocks to hinder its free flow in me.
But this must be a conscious decision on my part. I must cry out to the Holy Spirit continually, “Lord, convict me each time I defile myself.” David made this kind of determination. He wrote, “I am purposed that my mouth shall not transgress” (Psalm 17:3). “Set a watch, O Lord, before my mouth; keep the door of my lips” (141:3).
You may wonder, “Is it really possible to control the tongue, to purpose not to sin with the mouth?” David answers with this testimony: “I said, I will take heed to my ways, that I sin not with my tongue: I will keep my mouth with a bridle, while the wicked is before me” (39:1). He’s saying, in essence, “Every time I mount a horse, I have to put a bridle in its mouth. And as surely as I do that with my horse, I have to do it with my tongue.”