"But the Lord Knows Their Heart" is Precisely Their Problem

I was thinking about the phrase: "But the Lord knows their heart." I usually hear this applied to situations where a "Christian" is not acting like a Christian, and one of their loved ones defends their actions. I also hear this when people die who did not know the Lord...or at least did not seem to know Him. And every time I hear it, it rubs me the wrong way. Sometimes I concede and think to myself, "They're right...I don't know their heart. I better watch myself." And that in itself is true: I can not read a person's heart, and being prone to mistakes I sure as heck better watch myself. However, along with confessing what goes on in my head when this common phrase is spoken, I'd like to explore what the Bible says about this...

I guess first it would be appropriate to see where people are getting this idea from. Perhaps it is Acts 15:8 - "And God, who knows the heart, bore witness to them by giving them the Holy Spirit just as he did us." Or maybe it is from Revelation 2:23 - "...I am he who searches mind and heart, and I will give to each of you as your works deserve." In fact, there are probably tons of verses dealing with God and his ability to see the intents of the heart. Therefore, if someone says "God knows their heart", they speak absolute and unshakable truth. But when that is said, there is usually a different meaning behind it than when the Bible talks about the heart of men. For instance, Jeremiah 17:9 says, "The heart is deceitful above all else, and it is desperately sick; who can understand it?" Or this passage from John: "Now when he was in Jerusalem at the Passover Feast, many believed in his name when they saw the signs that he was doing. But Jesus on his part did not entrust himself to them, because he knew all people and needed no one to bear witness about man, for he himself knew what was in man." What are we seeing here? We can see that when the Bible talks about the heart of men, it is negative 99.9% of the time, usually saying things like man cannot be trusted, or man deceives himself, or man HATES God. So then, why do we speak about the hearts of men in a different way, implying their "deep-down" goodness? The truth is, the concept of a good human heart is foreign to the Bible unless it has been regenerated and quickened by the Holy Spirit.

All this to say, the phrase "But God knows their heart" should serve to make us tremble rather than making us more comfortable with who humans are. I realize that we want to believe the best about people, but even the best a human being can offer is deserving of Hell. Perhaps this phrase should even be used as motivation for evangelism in some situations; that is, when we start to think "Hey, he seems like a great guy. Maybe he does know the Lord." We can remind ourselves that the Lord knows the heart and does not justify human sin.