“Holy Cross”
Original sermon given on Sunday, September 14, 2025 written and delivered by Pastor Jeff Leininger at First Saint Paul’s Lutheran Church.
Watch the sermon live.
“Holy Cross”
1 Corinthians 1.18-24
& John 3.13-17
In the name of the Living God and His Risen Christ. Amen.
It is arguably the most important battle ever fought in Western History. Before he was called “Emperor” or “Saint,” Constantine was but one more competing general in a fragmenting Roman world. But at the battle of the Milvian Bridge in 312 AD, he defeated his pagan rival Maxentius. What is remarkable is how Constantine won the battle. Yes, he was a great general and warrior. Yes, he had some great soldiers brought all the way from Brittan. Yes, he had met Maxentius on advantageous ground. But Constantine did not attribute victory to any of these factors. You see, the evening before, with the armies preparing for battle, Constantine saw a vision in the sky of either a cross, or the Chi / Row—a symbol of Christ using the first two Greek letters in his name. Accounts differ and speculation abounds, but whatever it was, the vision included the words, “in hoc signo vinces / in this sign conquer.” This convinced Constantine to engrave a Christian symbol on the shields of his soldiers. They won the victory that day, and our world has never been the same.
Now, you can google all the historic controversy about what exactly he saw in that vision when you get home after church. For our purposes, the world changed that day because the emperor then became a Christian emperor, eventually moving Christianity from a small Jewish sect called the “way” to eventually becoming the official religion of the “Holy” Roman Empire.
Let’s get to September 14: a couple of decades later, Constantine’s pious Christian mother, Helena, went on a quest to discover both the true site of the crucifixion and the true cross itself. Legend has it that she found both, and on September 14, 335 the Church of the Holy Sepulcher was built in Jerusalem over that location in honor of Constantine’s victory. This is the traditional site of the crucifixion to this day.
But none of this is why we observe “Holy Cross”, on September 14.
We do not celebrate an emperor’s victory today, however historically important. We do not celebrate finding the true cross, however historically possible. We do not even celebrate Christianity becoming the dominant religion in Western Civilization. Today, we remember that it is precisely “in this sign” that we too conquer. We overcome not earthly enemies, nor kingdoms of temporal power, nor political ideologies, but we overcome the greatest enemies of sin, death, and the devil in the conquering sign of the cross.
St. Paul understood the power of the cross. But he also understood that its power is found, paradoxically, in its folly. From today’s epistle, “For the word of the cross is folly to those who are perishing, but to us who are being saved it is the power of God” (1 Cor. 1.18). The cross was an instrument of death. It was a symbol of ultimate defeat and destruction. On crosses people were brutally and shamefully killed. And yet we dare to say, along with St. Paul, that this is the power of God and the wisdom of God.
Why does St. Paul describe the cross as “foolishness” to those who are perishing? The cross is so different from any other ideology because at the very weakest, most vulnerable, most shameful point possible, God is to be found. God is revealed there. This is so counter to this world’s wisdom, where in military or political or economic victory, God (or, the gods) are to be found. If you were victorious in battle, wealthy, powerful, persuasive, given the ability to conquer, exploit, or manipulate others you were considered highly favored by the gods.
But Christians follow a crucified and risen Lord, which means that God is to be found in solidarity with and among the seemingly defeated, the poor, the forgotten and forsaken. If God can show up in love at the cross, he could show up anywhere… for anyone, and even for you this morning too, regardless of life’s battles you’ve lost or won.
So, you see, when we see the cross, we are moved by this great paradox: the death of the Son of God meant ultimate victory. This is foolishness; this is folly. But we believe that in the innocent death of Jesus, God was reconciling the world to himself. We say that in the brutal suffering of Christ, our suffering, no matter how difficult, is given meaning. We maintain that, while others laugh and scoff and stumble over this sign, we weep and are moved and are uplifted by it, for it is the sign of all signs that we will one day conquer too.
One of Martin Luther’s greatest contributions to Christianity was his “theology of the cross.” There’s lots to explore here, but two things to remember this morning. God is revealed in suffering; and God does not abandon us in suffering. In the suffering of Christ on the cross, we are drawn to God. In our own suffering he draws near to us, refuses to abandon us. Even more, Luther held that the grace and mercy of God cannot be found outside of the suffering of the cross. Here, we might say, is God’s heartbeat of love for us.
Martin Luther published a sermon in 1519 entitled “A Sermon on Preparing to Die.” It’s not the most cheerful title — perhaps he could have used some better marketing strategies. (Yet, I suppose death and the inevitability of death tends to focus the soul, so maybe it’s not such a bad title.) In any case, his “Sermon on Preparing to Die” spills a lot of ink on the cross.
Luther writes, “Grace and mercy are there where Christ on the cross takes your sin from you, bears it for you, and destroys it. To believe this firmly, to keep it before your eyes and not to doubt it, means to view the picture of Christ and to engrave it [on] yourself… Here sins are [no longer] sins, for here they are overcome and swallowed up in Christ. He takes your death upon himself and [removes] it so that it may not harm you… Likewise he also takes your sins upon himself and overcomes them with his righteousness out of sheer mercy… Never, therefore, let [the Cross] be erased from your vision. Seek yourself only in Christ and not in yourself and you will find yourself in him eternally.”[1]
On this “Holy Cross Day”, we remember that the cross is holy because on it the holy son of God made us holy. And on this “Holy Cross Day,” we remember that because of the cross, we can know that in all circumstances, in all suffering, in every persecution and every season in life, God is still there for me. “In this sign conquer.”
Come soon Lord Jesus. Amen.
[1] “A Sermon on Preparing to Die”, AE 42, p. 105, adapted