Hebrews 9:13–14: “For if the blood of bulls and goats and the ashes of a heifer, sprinkling the unclean, sanctifies for the purifying of the flesh, how much more shall the blood of Christ, who through the eternal Spirit offered Himself without spot to God, cleanse your conscience from dead works to serve the living God?”

July 30th, 2022 by Pastor Ed in devotional

The Greek word translated “cleanse” is katharizo, which means “to purge.” This word appears 30 times in the New Testament, and it means “to cleanse and free from filth.” It is the same word used in the gospels to describe how Jesus healed the leper’s wounds. These verses tell us that Jesus Christ’s blood cleanses, purges, frees us, from filth. This is a strange idea, since we know blood as something that stains or soils. It is something that needs to be cleaned up. But here it is something that cleans.

Fascinatingly, modern physiology has proven that inside our bodies, human blood actually does act as a cleansing fluid, carrying away potentially harmful products of metabolism to be filtered by our kidneys and liver. Famous hand surgeon Henry Brand explained it this way in Christianity Today:

All that we have learned about physiology in recent years confirmed the accuracy of the still-jarring juxtaposition of blood and cleansing. I suggest a simple experiment if you truly wish to grasp the function of blood as a cleansing agent. Find a blood pressure kit and wrap the cuff around your upper arm. When it is in position, have a friend pump it up to about 200 mm. of mercury, a sufficient pressure to stop the flow of blood in your arm. Initially your arm will feel an uncomfortable tightness beneath the cuff.

Now comes the revealing part of the experiment: perform any easy task with your cuffed arm. Merely flex your finger and make a fist about ten times in succession, or cut paper with scissors, or drive a nail into wood with a hammer. The first few movements will seem quite normal as the muscles obediently contract and relax. Then you will feel a slight weakness. Almost without warning a hot flash of pain will strike, after maybe ten movements. Your muscles will cramp. If you force yourself to continue this simple task, you will likely cry out in absolute agony. Finally, you cannot force yourself to continue; the pain overwhelms you. When your release the tourniquet and air escapes from the cuff, blood will rush into your aching arm and a wonderful sense of relief will soothe your muscles.

Physiologically, you have just experienced the cleansing of the blood. While the blood supply to your arm was shut off, you forced your muscles to keep working. As they converted oxygen into energy, they produced certain waste products (metabolites) that are normally flushed away instantly in the bloodstream. Due to the constricted blood flow, however, these metabolites accumulated in your cells. They were not “cleansed” by the swirling stream of blood, and therefore in a few minutes you felt the agony of retained toxins.

That is the ability of the blood to cleanse in a physical sense, and it gives us something of an illustration of what Jesus’ blood does to us on a spiritual level. His blood has the power to take the blackest heart and wash (purge) sin, making it whiter than snow. As Isaiah recorded: “‘Come now, and let us reason together,’ / Says the LORD, / ‘Though your sins are like scarlet, / They shall be as white as snow; / Though they are red like crimson, / They shall be as wool'” (Isa. 1:18). In the first covenant, God decreed animal sacrifices for sin, but the blood of bulls and goats only covered sin and did not purge it. A purging from sin can only come by the blood of Jesus Christ. The death of Jesus, the perfect sacrifice of the new covenant, finally put an end to sin’s stain on human souls. He cleanses and frees from sin everyone who surrenders to Him.

“LORD, we gratefully bow before You and ask You to apply the cleansing power of Your blood to our sins today.”