Fifteenth Sunday after Pentecost

Pentecost 15 (Proper 17), September 1, 2024 A Defiled Heart Made Clean Text: Mark 7:14–23 Other Lessons: Deuteronomy 4:1–2, 6–9; Psalm 119:129–136; Ephesians 6:10–20 Sermon Theme: God takes our defiled hearts and creates clean, fruitful hearts by his Gospel. Sermon Goal: That you confess that your hearts produce nothing but evil but that by the Gospel God creates in you new, clean hearts that desire to keep His commandments. Based on a sermon outline by Rev. Stephen K. Preus.

Sermon: “Just follow your heart.” Undoubtedly you’ve heard this popular advice from someone before. A sinful heart is the source of a sinful intellect and intuition, a sinful understanding and will. That’s the way the Scriptures speak of the heart. Thus, the solution to “Just follow your heart” cannot be “Just follow your intellect” or “Just follow your intuition.” Both of these are defiled as well. The only real solution is God acting outside of us and for our benefit. And that is what he does! God Takes Our Defiled Hearts and Creates Clean, Fruitful Hearts by His Gospel.

Every heart is by nature defiled and yields only evil. The Pharisees and scribes lived as if something else defiled people. They believed and lived as if what defiled a person is what goes into him—like the right foods eaten the right ways—which are really mere outward works, even those invented by man instead of those commanded by God.

He teaches the crowd that “there is nothing outside a person that by going into him can defile him, but the things that come out of a person are what defile him” (v 15). Jesus did not want the crowd misled by the moralism of the Pharisees.

Jesus corrected the disciples’ false belief to prepare them to teach others the same. He teaches the disciples that it is not what goes into a person that defiles him, since what goes in enters not the heart but the stomach and exits to the latrine. It is what comes out of a person that defiles him, because “from within, out of the heart of man, come evil thoughts” and so much more (v 21). Original sin causes actual sins. We are not sinners because we sin; we sin because we are sinners. And this is true of us all, but not Christ. God creates new, clean hearts in us through Christ by his Spirit-filled Gospel. This clean heart has existed only in one man: the God-man, Jesus Christ. His heart was pure and holy, since he is God’s Son made flesh from the virgin Mary (Lk 1:35). From his heart came forth love for both God and man, fulfilling God’s Law for our sakes (Gal 4:4–5).

From his heart flowed water and blood as he was pierced for our defiled hearts (Jn 19:34), cleansing us by his atoning blood (cf Lev 16:30).

This shows us the Father’s heart of love for us, that he gave his only Son into death for our sin (Rom 8:32).Through the Spirit-filled Gospel, God gives us what Jesus gained on the cross.

Christ rose and sent the Holy Spirit to take what is his and “declare it to you” (Jn 16:14). So all Jesus accomplished with his holy heart, the Spirit now declares to be your own.

By the Gospel, he washes you thoroughly from your iniquity and cleanses you from your sin, making you whiter than snow and creating in you a clean heart (Ps 51:2, 7b, 10; cf Jn 15:3).

Through faith alone, our hearts are newly created by this Spirit-filled Gospel (Acts 15:9). Through faith, we receive and benefit from what Christ gained in his life, death, and resurrection and what the Spirit gives us in the Gospel. This faith God gives us as a gift of his grace alone (Eph 2:8).

With such hearts, we can approach God’s throne of grace and “draw near with a true heart in full assurance of faith, with our hearts sprinkled clean from an evil conscience and our bodies washed with pure water” (Heb 10:22).

Then, with our newly created hearts, we bear fruit by the strength God alone gives. We must remember that our sinful hearts were not removed in Baptism but remain in us until we die. So in spite of our faith and sanctified good intentions, those evil thoughts and that catalogue of vices will continually seek to defile our hearts (Rom 7:18–19).

But we return to the cleansing of our baptism by confessing our sins and receiving in faith the absolution: “If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness” (1 Jn 1:9).

And our newly purified hearts are zealous for good works (Titus 2:14). Just as evil thoughts flow from the defiled heart, so “the springs of life” (Prov 4:23) and “fruit of the Spirit” (Gal 5:22–23) flow from the heart that’s cleansed by the Spirit-filled Gospel (cf Mt 23:26). But we do not look to our hearts to decide what good works are. Instead, God prepared for us beforehand what those good works are to be (Eph 2:10). They are done according to his Law and lived out in our assorted stations in life within the three estates, as Scripture teaches (see Old Testament Reading).

Our strength for these works of love comes only from the heart purified by Jesus’ blood (Heb 9:14).

Paul sums it up: “The aim of our charge is love that issues from a pure heart and a good conscience and a sincere faith” (1 Tim 1:5).

So find strength in the purifying blood of Jesus. Once shed. Continually given in his Supper. For you. And you have a defiled heart made clean and fruitful once more. Amen.