We can’t know what’s in someone’s heart?

Much like a secret chamber you may read about in a mystery novel, the heart contains secret passageways, false walls, and poorly lit paths. 

Yet for all its complexity, the heart isn’t inscrutable. Like a second-rate poker player, it has tells. The heart has a way of betraying its most secret intentions.

Such matters of the heart seem lost on a certain class of Christian leaders. A small but influential group of evangelical figureheads acts as if it’s brand new information that we can read the heart, instead of an established biblical reality. 

In the days of President Trump—though not unique to him—this phenomenon arises when holy-ish huddles invest themselves in politicians who claim to have their back. And when this politician inevitably says or does something to contradict the very faith these leaders proclaim—and when the hairs on Christian necks stand up—they rush to repeat what has become their mantra: “We can’t know what’s in someone’s heart,” and go on to assure the flock of a backroom confession from the perpetrator and a joy down in their hearts—just deep, deep down.

While played from the bottom of the deck like a spiritual trump card, the phrase holds some theological water. “Only God can judge me,” the stuff of defiant lyrics and unfortunate tattoos, meets the criteria of ultimate spiritual reality. 

Behavior exposes the lay of the (heart)land. 

God remains the only one who can fully discern our motives and desires, who can see through us to the presence of faith—and praise him for that. Historically, humans trying to play his part find divine judgment too heavy a burden to lift with integrity.

But the words “We can’t know what’s in someone’s heart” ring hollow because they dispute the very words of Jesus who said who we are shows in what we say and what we do. Our mouths cannot work apart from our hearts. Everything stirred up and sloshing around inside us eventually spills from our lips. Our worst moments do not define us, but we cannot divorce ourselves from them either. 

We cannot know all that lies within a person’s heart, but their public behavior yields a pretty good lay of the land.

If someone constantly speaks belittling words or goes out of their way to make others look small, we can safely assume pride makes their hearts swell three sizes too big. 

If someone’s speech always circles back around to themselves—their rights, their needs, the way they are treated—we conclude they have not internalized “He must increase, but I must decrease.”

James tells us blessings and curses cannot come out of the same mouth. Denigrating entire populations and using speech as a shear to prune another’s humanity leaves listeners thinking that the speaker likely foregoes blessings off mic too. 

Jesus called out people who honored him with their lips, yet whose hearts were miles away. What does it say about the state of a heart if a person cannot manage to honor God with their lips? 

Love ultimately expresses spiritual identity, Jesus said. The love you wear reveals the love that lives inside. 

People of true faith and good intent can disagree on what love converted into policy looks like, but the love that seals a disciple’s heart cannot help but work itself out in tone, temperament, and relationships. Explaining a lack of public love with promises of private evidence vibrates with biblical dishonesty.

The ultimate proof of our faith comes in our fruit—the love, joy, peace, patience, kindness, goodness, faithfulness, gentleness, and self-control—which grow tall and mature in the soil of God’s love. Where this fruit fails to ripen, or dies on the vine, we find significant evidence of spiritual rot or no spirituality at all.

To be clear, the standard is not perfection, but progress. He does not ask for complete desires but rather, as Jerry Bridges helpfully writes about, asks that desires bend in the direction of holiness. We might speak harshly or act rashly, but recognition and repentance follow. We never double down on our sins; instead, we come and die. 

Discipleship takes a lifetime, and God sees the entire path in ways we cannot. And in that path he has driven mile markers, indicating progress and confirming our direction. If we see none, it might be time to change course before we wander too far down the wrong path.

Use your spiritual IQ.

Confusion of God’s will remains one of the evangelical’s fatal flaws. Christians beat their chests to know God’s secret will—what job to take, whom to marry—while ignoring his revealed will, principles we must get busy following and promises meant to mold our lives. 

“We can’t know what’s in someone’s heart” commits the same error. The speaker rightly affirms we can’t presume upon God’s secret will, yet neglects clues he left behind. Those words weren’t built to defend the indefensible or justify public-facing transgressions.

A few words to my brothers and sisters whose fifteen minutes of Christian influence are ticking off the clock, yet ignore the waving hands at the back of the room telling them time’s up: We hear you speaking from both sides of your mouth, telling us we must charge the public square even as you create the extra-biblical category of private Christian.

Stop shifting the burden of proof from the Bible to us.

We will no longer recognize a baptism that comes by your words alone, only the baptism that comes by water and fire.  

Don’t tell us, “Stick to the gospel,” when you’ve failed to remember the effects the gospel has on a saint.

Every good investigative journalist memorizes the phrase “follow the money.” Track the receipts, the bank statements, and eventually you come face-to-face with the players in a scandal. For Christians seeking to sort a public figure’s statements of faith, I suggest the axiom “follow the heart.”

Check the receipts—we’ll either find God or a gaping hole.