What Does it Mean to be Pure? Or, How We Often Minimize What Jesus Really Means When He Says We are to Be "Pure in Heart"
Our daughter’s name is Kate, which means “pure.”
The other night I came in to tuck her in a bit late, and she said “I just got done praying.” Which is fantastic (she’s 6). I said to her “what did you pray for?” One of the things she said was: “I prayed that I would be pure, just like my name means.”
That is really, really great. Lord, may it be so.
Kate’s prayer echoes, of course, Matthew 5:8 (though she doesn’t know it!): “Blessed are the pure in heart, for they shall see God.”
Now, being 6, she probably has a very small idea of what it means to be “pure.” But most of us who are adults do, too.
Most of think of purity mainly in relation to lust. To be pure is to refrain from lustful thoughts and lustful desires. That is critically important (Matthew 5:27-30). And, it flows from being pure in heart. But that is not the main meaning of purity. The main meaning is far, far more.
Jesus expounds on what it means to be “pure in heart” in two other places in the Sermon on the Mount:
“Do not lay up for yourselves treasures on earth . . . but lay up for yourselves treasure sin heaven … for where your treasure is, there your heart will be also. The eye is the lamp of the body. So, if your eye is healthy [literally: "single"], your whole body will be full of light, but if your eye is bad, your whole body will be full of darkness. If then the light in you is darkness, how great is the darkness! No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money” (Matthew 6:19-24).
“But seek first the kingdom of God and his righteousness, and all these things will be added to you” (Matthew 6:33).
It was always puzzling to me what Jesus meant by “the eye is the lamp of the body” in 6:22 But if you look at it, you see he has simply switched metaphors.
Jesus just got done telling us to lay up treasures in heaven, not on earth, so that our heart will be in heaven — not on earth. Then he says “the eye is the lamp of the body” and that if it is healthy, everything else is right for you. In other words, what he has just said about our heart — fix it on heaven — he is expounding on, only now using the metaphor of the “eye.”
He is saying, in effect, “let your eye be single — be focused on just one thing, on heavenly realities.” Let your eye — your heart — be set on God.
He then re-iterates this in different terms in the verse next verse, setting it against the backdrop of the biggest competitor to God for many: money. “No one can serve two masters, for either he will hate the one and love the other, or he will be devoted to the one and despise the other. You cannot serve God and money.”
In other words, once again, you cannot have two ultimate priorities. “No one can serve two masters.” You can only have one master, one ultimate priority, and it is to be God.
Jesus then applies this to worry (for worry is often a result of not having our priorities straight), and then re-states the point again in different words: “But seek first the kingdom of God and his righteousness, and all these things will be added to you” (6:33). Seek first the kingdom of God. Let that, and that only, be your ultimate priority and aim. If you have other ultimate aims, your heart is not “pure” — it is not single and wholly devoted to God, but divided. The pure heart is the heart that is fully devoted to God, set on heaven, loving him and not ultimately other things like money.
Does this make us so heavenly minded we are no earthly good? Is Jesus saying “don’t care anything about this world? Let ‘the things of earth become strangely dim’?” No. To have God as your ultimate priority is not to become a hermit and care nothing for this life; it is rather to care even more for this life — but for a different reason. We now care about it because we care about loving others and living out the priorities of God’s kingdom in the face of injustice and hardship and trouble — as Jesus said right at the start of the sermon: “Let your light so shine before men that they may see your good works and give glory to your Father in heaven” (Matthew 5:16). Love for God lives itself out through love for our neighbor (1 John 4:21).
Bringing this all back to Matthew 5:8: To be “pure in heart” means to be single-minded for the glory of God. It is to have God and his kingdom as your ultimate priority, with no competitors. It is to serve one master, not two. It is to have a single eye, treasuring heaven and Jesus more than anything in this world. It is for your ultimate aim and priority and value in life to be knowing Jesus Christ and, from that, living a life of good works so that he, not you, is glorified (Matthew 5:16).
Clearly, the result of this will be that you are not ruled by lust (5:27-30) — or anger (5:21-26), or undependability (5:33-37), or retaliation (5:38-41), or stinginess (5:42), or lack of grace and generosity (5:43-48), or love of the praise of men (6:1-4), or money (6:24). The entire sermon, in a sense, is an exposition of what it looks like when your heart is pure. And so we see that having a pure heart is not simply a matter of not lusting, but a whole lot more. And, beyond that, we see that all of these qualities of a pure heart stem from the fact that you are single-mindedly devoted to the glory of God.
That’s what it means to be “pure in heart” — and that’s what I pray for my daughter.