Updated: Feb 6, 2021
Okay. Humor me for a moment.
In the event you are one of those intellects that know the responses to this pop quiz, I ask you to trek with me (and the others) as we challenge our brains on the subject of human anatomy parts.
What are Venae cavae?
What is Cerumen?
Do you know what the accessory lacrimal glands are?
If you are like me and did not readily know the meaning of each medical term, please don’t allow yourself to feel any other way aside from uninformed.
The venae cavae (Latin for "hollow veins”) are two large veins that return deoxygenated blood from the body into the heart. The vena cava has two parts: the superior vena cava and the inferior vena cava. The superior vena cava carries blood from the head, neck, arms, and chest. The inferior vena cava carries blood from the legs, feet, and organs in the abdomen and pelvis. The vena cava is the largest vein in the body.
Cerumen, which is a medical term, also goes by the unattractive term known as Earwax. It gets its name from the waxy, sticky texture - but earwax is not a wax. The exact recipe for earwax requires a good dose of sebum (a body secretion made up mostly of fat), skin cells, sweat and dirt. Cerumen or earwax is pretty important stuff. It is produced by the ear to clean and protect itself. It is secreted by glands in the skin that line the outer half of your ear canals. The wax and tiny hairs in these passages trap dust and other foreign particles that could damage deeper structures, such as your eardrums.
The accessory lacrimal glands (Krause's glands) are small, mucous accessory lacrimal glands that are found underneath the eyelid where the upper and lower conjuctivae meet. The function of these glands are to produce tears which are secreted onto the surface of the conjuctiva.
The preceding survey was not intended to shame you for not knowing the correct answers. To the contrary! The insight should serve as valuable.
My lack of knowledge and your lack of knowledge about certain anatomy parts doesn’t negate the fact the distinct parts do in fact exist. And not only do they exist, but they are also of great significance.
The same can be said for your role in the body of Christ.
In speaking about the Scriptural phrase, the body of Christ, I am referring to the local and universal church in the metaphorical sense.
I would like to encourage you to read 1 Corinthians 12:12 through 31. Read the passage closely and thoughtfully. Read it as though you were one of the “parts” being spoken to directly.
Pause and linger on verse 18:
But in fact God has placed the parts in the body, every one of them, just as He wanted them to be (New International Version).
After you download and process your predestination, reread verses 22-24. And then finally, read aloud verse 25.
25 so that there should be NO DIVISION in the body, but that its parts should have equal concern for each other [emphasis added] (NIV).
…No division in the body.
God, help us with that.
At the time of this writing, I would describe the body of Christ as appearing to have an Autoimmune disease—an overactive immune system that attacks its own tissues instead of fighting off pathogens.
Can you imagine members of the body of Christ—those who have been:
Called—invited by name (Ephe. 4:1)
Chosen—selected, picked out (Ephe. 1:4)
Justified—pardoned and cleared from guilt; declared and pronounced righteous (Rom. 5:1),
Sanctified—separated from the profane and irreverent and purified internally by the renewing of the soul…
Can you imagine any part of the Lord’s body behaving in a manner that would be destructive to another?
Or to think your superior vena cava would choose not to communicate with other dependent organs, thus refusing to carry blood from your head, neck, arms, and chest, effectively disrupting your bodily functions and rendering you incapacitated.
Such a situation would be critical.
Whatever “part” of the body you are, accept your importance and responsibility. You have been called and chosen and set in place exactly where God would have you to be. Assume He knew exactly what He was doing.
Just as the Venae cavae, cerumen, and the lacrimal gland have their role, so do you.
From Him the whole body, joined and held together by every supporting ligament, grows and builds itself up in love, as each part does its work (Ephe. 4:16 NIV). 
Elwell, W. A., & Comfort, P. W. (2001). In Tyndale Bible dictionary (p. 231). Wheaton, IL: Tyndale House Publishers.
The Holy Bible: New International Version. (1984). (Eph 4:16). Grand Rapids, MI: Zondervan.