During our midweek services this year, I will be preaching on our stained glass windows. Then, later in the service, we will dedicate the window on which I have preached. We will begin today with the Trinity window. That’s the window over there, the last window on the right side. There is also a sketch of this window on your bulletin cover.

This window is to remind us that the only God we worship, as Christians, is the Triune God. That means that the God we worship is one. There are not three Gods in the Christian faith, but only one. But within that one Godhead are three separate, but completely equal, persons: the Father, the Son, and the Holy Spirit. This is something that our reason cannot entirely fathom. We do not completely comprehend how one being can, at the same time, be three separate persons. But, as Christians, this is what we believe and confess about our God, because this the way that He has revealed Himself to us in the Holy Scriptures. To worship any other god besides the Triune God is idolatry; it is to worship a false God. That means, for instance, that anyone who denies that Jesus is true God, equal to the Father and Holy Spirit, does not believe in the true God. Or anyone who believes that the Holy Spirit is only a force and not a real person, is worshipping an idol. Christians worship only the Triune God: one God, three equal persons. That is what is depicted in our Trinity window.

First of all, notice the triangle. The triangle is probably the oldest symbol of the Trinity. Christians have been using this symbol to confess the Triune God for well over 1500 years. This is not just any kind of triangle. It is an equilateral triangle. That means that each side and each angle in the triangle is equal. So we have one triangle, representing the fact that there is only one God. But we also have three equal sides, representing the fact that within that one Godhead are three separate persons who are co-equal: Father, Son, and Holy Spirit.

Weaving through each of the sides of the triangle is a circle. This, of course divides the circle into three equal parts, once again conveying the one God, three persons of the Trinity, just as the triangle does. But there is something more in the circle. In Christian symbolism, the circle always represents eternity. A circle, like eternity, has no beginning and no end. So the circle in our window reminds us that the three persons in the Trinity are not only co-equal, but also co-eternal. No one person existed before the other, but the Father has always existed, the Son has always existed, and the Holy Spirit has always existed.

Then there is one other symbol to notice in our window. Right in the middle of the circle and triangle is the cross. This is very rich symbolism. This tells us that there is no other way for a person to come to the Triune God except through the cross, where Christ was sacrificed. There is no other way for a person to worship the true God, or pray to Him, or serve Him, than through the blood of Christ that was shed on that cross. We are sinners who cannot approach God through our own merits or worthiness, but only through the cross.

But the cross also tells us something else. It tells us of the great love of our Triune God, Who has saved us from our sins and given us eternal life. And this Trinity window with the cross in the middle reminds us that each person of the Godhead is involved in that cross. The Father was involved in our salvation, the Son was involved in our salvation, and the Holy Spirit was involved in our salvation. That’s why I chose this text for our sermon, for in it we see the Triune God with the cross in the middle. It’s the perfect text to describe what this window portrays. Let’s take a look at this for the next few minutes. Let’s see how each person of the Trinity is involved in the cross for our salvation.

But God is Father also in another sense. Not only is He our Father, but He is also the Father of our Lord Jesus Christ. And this is especially stressed in our text. While we are children of God through adoption, Jesus is a natural child. He is of the same essence and nature as the Father. He is the Son who has been with the Father from all eternity.

It is this Son, Jesus Christ, that our text says God the Father gave into death. There is the cross in our window. God the Father gave His Son to die on the cross. Why? Our text says it is because He so loved the world. Sin had separated us from God. It had brought eternal death upon us. But God so loved the world that He gave His only begotten Son, Jesus Christ, to die as sacrifice for our sins. That’s how the Father is involved in the cross. He gave His dear Son upon it to make atonement for our sins.

As we confess in Luther’s explanation to the third article, “I cannot by my own reason or strength believe in Jesus Christ my Lord or come to Him, but the Holy Spirit has called me by the Gospel.” The Holy Spirit’s involvement with the cross is that He brings to us personally the benefits that Christ earned for us there. He does this through baptism, the Lord’s Supper, and the preaching of the Gospel.

So, this is our Trinity window. There is only one God. But in this Godhead are three separate persons, equal in power and majesty: the Father, the Son, and the Holy Spirit. And in the middle is the cross, as a reminder and confession that it is through that cross that this Triune God gives us salvation and eternal life.

It is clearly appropriate that one of our windows depicts this Triune God. For that is the only God who is worshipped in our church. We began our Christian life baptized into the name of this God. Then, when our earthly life comes to an end, His name will be spoken over us again, as our bodies are laid to rest to await the final resurrection. We begin and end our worship services in the name of the Triune God. And, in fact, His name is spoken throughout our divine service: in the Creed, the hymns, and almost every part of our liturgy.