Love is when a player cares that another player gains points in the game.

Love is the central concept of Christianity. God is love. So it’s a breathtaking accomplishment by Satan that our culture has such a cloudy understanding of what love is. We overuse the word, intending different meanings. We throw around Greek words for different contexts of love to make it even more confusing.

Economics helped me develop a simple concept of love that I want to share. Shrinking life down into simple models can help clarify essential concepts—like looking at an architectural model of a house.

Imagine that life is like playing a game. You want to gather as many points as you can, and there are different ways to win points. Think of the points as happiness or “utility”. To an extent, we each decide what gives us points, but there are common things people tend to like. Eating a good meal—ding! Driving a fancy car—ding! Feeling like a good person—ding!

So far, I have described players in the game of life as selfish. It’s all about what the player consumes and feels. Love is when a player cares that another player gains points in the game. In economics-speak, love is including another person’s utility in your “utility function.”

In contrast, liking somebody is when they satisfy something in your own utility function. They scratch your itch. In theory—like in some dramatic movie—you could detest being with a person but care about their well-being. Imagine an estranged child or ex-spouse, who is difficult to be in the same room with, but you want the best for them. That’s someone you don’t like, but you do love.

Jesus described himself as being “in” the Father and invites us to be “in” him. (John 14:10) In each other’s utility functions. The game of winning the maximum number of points has not changed, but the rules of what grants points has changed. Self-sacrificial love is doing something your loved one likes but you don’t like. Presumably, you do it because the action gives you a net point gain, since they benefit more than you suffer.

Love need not be equal, in the sense that you might value another person’s wellbeing only a fraction of how much you value your own wellbeing. I might help a stranger self-sacrificially if the difference between their gain and my suffering is extreme—like sending $30/month so that a poor child in another country can attend school. But if the tradeoff nears parity—maybe their schooling costs $500/month—I likely won’t do it. I love that stranger a little, but not as much as I love myself.

“Greater love has no one than this: to lay down one’s life for one’s friends.” John 15:13

This understanding of love makes God’s instructions to “Love the Lord your God with all your heart and with all your soul and with all your mind” and to “Love your neighbor has yourself” even more daunting. Love everybody as much as myself? It sounds about as impossible as sending a camel through the eye of a needle. We’ll have to trust that “with God all things are possible.” (Matthew 22:37, 19:23-26)

Picking a spouse or partner is the context in which we talk the most about love, rightly so. Marriage is rife with imagery about becoming one person. One utility function. Even if you’re marrying a stranger, like in some old-school arranged marriage, you’re functionally committing to love them by throwing in your fate with theirs. What’s good for them will be good for you. Do not marry the person you admire, but the person you want to be. Those can be very different people.