Back in the day, before thermometers were a common thing in each medicine cabinet, parents used to "test" their children for fever by placing their lips on the forehead of the child. It seemed like an odd way to do it since we have seen people repeatedly use their hands laid across the forehead to "evaluate" the feverishness of another. Yet, it was a pretty doggone accurate process! More accurate than the hand - and the closest to the true determination of "fever" than anything other than a thermometer. The lips have a great deal of "sensitivity" receptors which allow them to be pretty accurate at interpreting what touches them.
Post a guard at my mouth, God, set a watch at the door of my lips. (Psalm 141:3 MSG)
The "sensitivity" receptors of our lips works both ways - affected by what leaves our mouths, and by what touches it! Maybe this is why David prayed for God to post a guard at his mouth - the entry and exit point for many a good or bad thing in his life! He is actually probably asking God to "tune up" his "sensitivity" to what both enters and leaves. I think we all need to pray this prayer at times. We need to "increase" the "sensitivity" of our lips - not just so we "feel" things better, but so we are able to evaluate things with more "receptors" - just like the mom testing her child for fever.
Two of the top areas of "sensitivity receptors" in our bodies are the lips and the fingertips. My mom suffers from having lost the feeling in her fingertips, not to mention her vision, so is it any wonder she uses her lips to assist her in identifying something she may not be sure about? The little candy wrappers with the twisted ends are a challenge for her. So, she puts the first end in her lips and then pulls with the fingers of one hand. In turn, she manages to open it. She has "adapted" to using what remains consistently "sensitive". Did you know your brain has dedicated more area to receiving the messages from your "sensitivity receptors" on your lips and from your fingertips than any other "receptor" area of your body? This means we have dedicated more "brain power" to interpreting these sensations to these two types of "receptors" than any other.
Sometimes I think we rely solely upon our "brain power" to do the interpreting of what it is we are receiving and sending out. I learned a little song a long time ago. It goes something like this:
"Holy Spirit come. Make my ears to hear, my eyes to see, my mouth to speak, my hands to reach, and my heart to reach out and touch the world with your love."
I wish I could credit for these lyrics, but I honestly don't even remember the title of the song, much less the author. Just know, these words have stuck with me in good times and bad. They have been sung over and over as I rely upon God doing just what these words imply - making me more sensitive to the things I need to be sensitive to and less sensitive to the other stuff.
We all have "sensitivity" receptors in our lives. One of the purposes of these receptors in our physical bodies is to keep us from harm. The receptors actually warn us to thins like hot, cold, bitter, or sweet. In a spiritual sense, we have been given similar "sensitivity" receptors in areas such as our emotions, mind, and spirit. It is good to post a watch over these in order to avoid undue injury. Without being aware of what "comes" and "goes" in our lives, we would be opened to all kinds of harmful stuff.
Let me give you an example of just a couple of these "sensitivity" receptors God has given to us in a spiritual sense. Maybe we hear words with a little "twang of jealousy" spoken. Our "ear" receptors have the ability to "filter out" the words to see the real intent of the one speaking them - to divide, to disgrace, or to destroy. Our "heart" receptors have an ability to reject or accept the words spoken - but first the "ear" receptors must do their job! If only one set of our receptors is working, we have a skewed perception. It is good to use the "sensitivity" receptors of our lips to judge how well the other receptors are working in our lives. You see, what comes "out" of our mouth is a good indicator of how well the other "receptors" are doing at protecting us from harmful input. When our ears have filtered out destructive input, our words are likely to reflect back words of grace to the one who spoke with the "twang of jealousy". When our hearts have not succumb to the emotional roller-coaster of latching onto the emotion behind the words heard, our speech will likely reveal words of forgiveness, not judgment.
The truth of the matter is - we need our "sensitivity receptors" to be touched by the Holy Spirit. Once we become familiar with the "sensation" created by his touch, we will not be as susceptible to allowing other things past the "receptors" of our ears, eyes, mouth, heart, or hands! Just sayin!