And he said, “These are they who have come out of the great tribulation; they have washed their robes and made them white in the blood of the Lamb.” Revelation 7:14
The cleansing power of blood is spoken of throughout the Bible. In Leviticus 14, for example, a priest sprinkled cleansing blood on a person with an infectious skin disease and on the mildewed walls of a house. In Revelation 7:14 we read that those who came out of the great tribulation “washed their robes and made them white in the blood of the Lamb.”
The trouble is, when we read verses like these, we struggle to make sense of them. For nothing in our modern culture corresponds to blood as a cleansing agent. After all, we use soap, detergent, or stain removers if we want to get something clean. Not blood. Blood is something we try to scrub off, not scrub with! There’s no advertising jingle saying, “Buy Rub a Dub-Dub and get cleansed by the blood.” Obviously that’s not the type of cleansing being referred to in the Bible.
Although the biblical writers didn’t know the physiology behind the metaphor, modern science reveals how the theological symbol fits perfectly with the medical understanding of blood as a cleansing agent. For the blood in our bodies performs the most amazing of janitorial duties. Dr. Paul Brand says, “No cell lies more than a hair’s breadth from a blood capillary, lest poisonous by-products pile up and cause ill effects. Through a basic chemical process of gas diffusion and transfer, individual red blood cells drifting along inside narrow capillaries simultaneously release their cargoes of fresh oxygen and absorb waste products (carbon dioxide, urea, and uric acid etc.) from these cells. The red cells then deliver the hazardous waste chemicals to organs that can dump them outside the body.” In other words, on a physiological level, blood sustains life by carrying away harmful metabolites in our bodies.
It’s the same on the spiritual level. Blood is needed to cleanse away the poison of sin. For sin is a paralyzing toxin that destroys our health, clogs our spiritual arteries, and interferes with our relationship with God and other people. That’s why, in the Old Testament, God established a covenant in which unblemished goats and bulls were ceremonially slaughtered and their blood shed for the forgiveness of sin. “For the life of a creature is in the blood, and I have given it to you to make atonement for yourselves on the altar; it is the blood that makes atonement for one’s life” Leviticus 17:11.
But this covenant was only temporary – a foreshadowing of what was yet to come. A new covenant was instituted when God sent Jesus Christ as the perfect, once for all, sacrifice for sin. He died and shed His blood as a ransom to set us “free from the sins committed under the first covenant” Hebrews 9:15. And, as a result of this ultimate blood sacrifice we can have forgiveness of sin and “our consciences cleansed from acts that lead to death” Hebrews 9:14.
Thus, we no longer have to approach God through the blood sacrifice of animals. The blood of Jesus Christ has made us clean. As it says in 1 John 1:7, “The blood of Jesus Christ His Son cleanses us from all sin” NKJV.