A picture of a toothbrush with a blurry sink in the background. This picture represents the process of having a clean mouth.

Do we have a clean mouth? All of us are “as an unclean thing, and all our righteousnesses are as filthy rags; and we all do fade as a leaf; and our iniquities, like the wind, have taken us away. And there is none that calleth upon thy name, that stirreth up himself to take hold of thee” (Isaiah 64:6).

As zealous as we might be, “the law justifies no person in the sight of God” (Galatians 3:11). “Therefore, by the deeds of the law there shall no flesh be justified in God’s sight” (Romans 3:20). As righteous as one wants to become, no one can “do the whole law” (Galatians 5:3). Thus, with the tongue, no one can call on the Lord purely.

What shall we say then? “Woe is me! For I am undone; because I am a human of unclean lips, and I dwell in the midst of a people of unclean lips” (Isaiah 6:5). Surely, our tongues cannot speak ourselves into heaven. Despite all the heavenly and unknown languages a person speaks, they cannot speak their way into heaven.

Now, are we to see our tongues as perverse? Are we to despair over the inability to speak purely? When we pray to God and prophecy, are we to doubt God’s acceptance of our prayers, or are we to prophecy in doubt? How can one pray to God with perverted lips and speak for God without a clean mouth?

The world would have us give up cleanliness and righteousness. “Don’t say the name of the Lord, for his name is too holy for your lips,” the world says. The world would have us to dwell on our own righteousness. “You mind as well give up doing God’s work because you’re imperfect, and you make too many mistakes,” the world says.

But the world ignores the holy one of Israel, Jesus Christ. It is far better to see not myself but Jesus Christ as the only route to righteousness and pure speech. That is to say, though our righteousnesses are filthy and inadequate, God’s “grace is sufficient for us” (2 Corinthians 12:9). Christians know that if they tried to figure out how to make their speech righteous, they would fry their brain. “If only I could stop making mistakes,” the world says.

The Christian, on the contrary, says “if only I could stop relying on myself to be perfect!” Yes, the Christian knows a mystery: that words do not come from the mouth but the overflowing of the heart (Luke 6:45). That is to say, words are the physical manifestation of a spiritual regurgitation—a vomit of the soul.

That is to say, when the world’s heart becomes full of evil, it vomits slander, curses, profane talk, contestation, and hateful words. When there is an overflow of Jesus Christ in a Christian’s heart, the mouth springs forth exhortation, praises, worship, and loving, encouraging and gentle words. Which is to say, the Christian speaks not of her or himself but of the overflow of God in her or himself.

So we read that “Not that we are sufficient of ourselves to think anything as of ourselves, but our sufficiency is of God” (2 Corinthians 3:5). Did not Moses stutter at the opportunity to lead the Israelites out of Egypt, but God would have given him the words and power to deliver the Israelites out of slavery (Exodus 4:10-16)?

The Christian knows that the Lord “will be with his or her mouth, and teach her or him what to say” (Exodus 4:12, John 14:26). The Christian says, “I am empty, dumb and weak, but the Lord will fill me up and strengthen me so I can have a clean mouth, speak, and fight.” This Christian reliance is different from the world because the world depends on its own grit, but is it not better to depend on the Lord?

To be sure, it is better to rely not on our weaknesses and imperfection but Jesus’s perfection and strength. When we rely on the Lord for strength and perfection, we rely on the strongest and faultless part of ourselves. Therefore, although we may know about our inadequacies and filthy mouth, we can be confident when we let the Lord speak for us, fill us up with righteousness, and transform us.