In his teaching on what exactly defiles a person, Jesus said, “Don’t you understand that whatever goes into the mouth enters the stomach and then passes out into the sewer? But the things that come out of the mouth come from the heart, and these things defile a person. For out of the heart come evil ideas, murder, adultery, sexual immorality, theft, false testimony, slander. These are the things that defile a person; it is not eating with unwashed hands that defiles a person.” (Matthew 15:17-20)
Notice that Jesus directs our attention to the human heart as the locus of all the evils in a person’s life. The reverse implication is therefore clear: if our hearts are pure, our whole life — everything about us — will be pure.
And as I’ve suggested before, purity of heart seems to come down to what our dominant motive is.
Consider the following. Let’s define a pristine motive like this: it is when everything we think, say, or do, is primarily motivated by a desire to please God. When that’s the case, our heart is pure. Why? Because everything in Jesus’ list of evils that come from the heart share one common denominator: pleasing self. That is to say, my daily activities are fueled by what I can get out of them, or by what’s in this or that relationship for me. And that corrupt motive — the DNA of an impure heart — defiles everything about us.
Conversely, when God gives us a new heart, one of its main features is that it wants to please God at all times and in every way. We concur when we make it clear to God and ourselves that we want everything we think, say, or do, to be subject to that motive. And while that is so, we safeguard our heart’s purity.
