I had a friend once who didn’t care much for hymns that had to do with blood. (And there really are some great old hymns about that.) You probably remember There is a fountain filled with blood, drawn from Immanuel’s veins; and sinners plunged beneath that flood lose all their guilty stains. Are you Washed in the Blood?; Alas, and Did My Savior Bleed; There Is Power in the Blood…

Why does that figure so strongly in Christian thought? You can easily understand why someone who doesn’t know about the Bible would consider this off-putting. But at the same time, there is this: In fact, the law requires that nearly everything be cleansed with blood, and without the shedding of blood there is no forgiveness (Hebrews 9:22 NIV).

It may be a strange thing to say, but shed blood is central to Christian worship and belief.

John, in his gospel, takes great pains to affirm that blood and water flowed from the crucified Christ. Why is that? Perhaps the answer lies in what that earlier passage of Hebrews is referencing—a ceremony that took place once a year on what is called the Day of Atonement.