The doctor asks little Johnny (Why are these kids always named little Johnny?) if he's willing to undergo the procedure. Johnny hesitates. His lower lip starts to tremble.
"Are you sure this will save my sister's life?" asks Johnny.
"Yes, son, you're the only one who can do this for her."
"OK," says Johnny, "if it's for my sister, I'll do it."
The nurse sets him up for the procedure, inserts the needle into his arm, and extracts the necessary blood. Little Johnny is weak and pale, but none the worse for wear, as he looks up at the doctor and asks, "When do I die?"
Only then does the doctor realize that Johnny had hesitated not at the prospect of getting stuck with a needle, but because he misunderstood him to be asking him to give his life for his sister. With uncommon courage and love, he'd agreed to do so.
Like Johnny's sister, each of us has a deadly condition. It's called sin. For us, Jesus gave not just his blood, but His life.