The following contains spoilers for BBC’s Sherlock season 4. Read on at your own peril.

I’ve always enjoyed a good mystery. I’ve written before about my affinity for Nancy Drew when I was younger and how I discovered a secret room, and I could name a dozen other detective stories I’ve enjoyed too. But let’s be honest: among all the literary detectives, there’s no one quite like Sherlock Holmes.

There have been a number of adaptations of the great detective’s exploits over the years, but one of my favorites is BBC’s TV series. Over the years, I’ve heard Sherlock praised for its high production value, its great acting, its suspenseful storytelling, its twists and turns. I appreciate all of those things, but I love it for the friendship between Sherlock and Watson. Benedict Cumberbatch and Martin Freeman play off of each other wonderfully, and I’ve loved watching Sherlock go from a man who “doesn’t have any friends” to someone who actually cares tremendously about the people in his life.

This last season blew me away. I’m sure some viewers will be angered by some of the writers’ choices, and under different circumstances, I might have been too. But for some reason I wasn’t—I think because the storylines fit the characters and choices they had made seasons ago.

After Mary Watson throws herself in front of a bullet to save Sherlock, the often arrogant and flippant detective is lost—confronted by a type of sacrificial love he didn’t know existed.

“In saving my life, she conferred a value on it,” he says. “It is a currency I do not know how to spend.”

It’s not often that a line of TV dialogue catches my attention for its beauty. This one made me pause my video and skip back to re-watch it.

In saving my life, she conferred a value on it.

It is a currency I do not know how to spend.

I mulled over the quote for a few days, trying to figure out why it struck me so, and what I came up with was this:

In saving my life, Jesus conferred a value on it. And that is a currency that I often do not know how to spend.

In the past, I have often tried to prove myself worthy of that conferred value. I’ve thought that by obeying my parents, getting good grades, being nice to people, serving in Sunday school or other volunteer positions, and reading my Bible every day, I could somehow repay the debt I owe Him. Though I knew (in theory at least) that any sin I committed or mistake I made would not make Him stop loving me, a part of me still believed that if I did what was right, He would love me more.

But I don’t think anymore that He saved me so that I could do more good things for Him. All of my righteous deeds are like filthy rags before Him—of course He wants my obedience rather than my sin, but He doesn’t need my good deeds. They could never repay my debt to Him, and I don’t think they are the type of currency He intended to give me when He gave His life.

Later in the season, when Sherlock is forced to choose between killing the two people he cares about most in the world, he chooses neither, instead showing that he is willing to sacrifice himself in their place.

Sherlock is arguably a very flawed character. He is arrogant, thoughtless, sometimes unfeeling, a drug addict, and at one point, even a murderer. But at that point in the story, I think he got it: the only worthy response to sacrifice is . . . sacrifice.

“This is my commandment, that you love one another as I have loved you. Greater love has no one than this, that someone lay down his life for his friends.” John 15:12-13

In giving His life for ours, Jesus conferred great value on us, that much is certain. Rather than good deeds, though, I think this is the type of currency He intended us to spend.

Love.

Grace.

Sacrifice.

Ironic for such a flawed detective to be a model of that. But then, maybe that makes sense. When someone gives their life for you, it changes you. And God chooses to demonstrate that to the world through us—these poor, puny, flawed creatures, clinging to faith in a Savior’s sacrifice.