Text: Isaiah 6:1-7
“Holy, holy, holy is the Lord of hosts; the whole earth is full of His glory!” (Isaiah 6:3, English Standard Version) These were the words of the angels in the throne room as they called out back and forth, giving praise to the eternal one God in three persons. They say, “holy,” not once but three times; once for each divine person. And yet, they say, “the whole earth is full of His glory.” The true God is the triune God: the one God who exists in three eternal, divine persons. Neither is greater or lesser than another, none is before or after another. This much is revealed to us in Scripture.
Today is Trinity Sunday. This week marks the shift in celebration from events in our Lord’s life to His teaching, and our growth in it as Christians. Holy Trinity is the only Church holiday devoted to a teaching of the Church. But, it’s not just a teaching; it is the divinely-revealed truth. There is no God but the God of the Bible, and He is triune. Rather than this teaching being a burden, as some would have us believe, the doctrine of the Trinity is a blessing – for by this teaching we learn to know our God, and ourselves, aright.
Before we go further, let’s talk about the text from Isaiah. As to his person, we don’t know much about Isaiah beyond his father’s name and the timeframe in which his ministry was conducted. Isaiah himself said that he prophesied during the reigns of Uzziah, Jotham, Ahaz, and Hezekiah. These were kings of Judah, who reigned in Jerusalem during a height of its power. During Isaiah’s ministry, which ran from about 740 to 680 B.C., Jerusalem’s influence was second only to the reigns of David and Solomon. While we don’t know much about Isaiah as a person, we know his doctrine. Isaiah, at times, has been called the fifth Gospel writer, for the promises of the Messiah – of His suffering, death, and resurrection, and the forgiveness we receive through the same – are sung all throughout his writing. Isaiah is also known for preaching of the Law against the decadent unbelief of Jerusalem. Our text today is the Lord’s calling of Isaiah to be a prophet.
Isaiah says, “In the year that King Uzziah died I saw the Lord sitting upon a throne, high and lifted up; and the train of His robe filled the temple.” (Is. 6:1) Above the Lord stood the seraphim, who called to each other, “Holy, holy, holy is the Lord of hosts.” The foundations of the temple were shaking from the voice of God, which reminds us of how Mt. Sinai rumbled while God spoke to Moses. The people of Israel were terrified at that, and wished they would die. So did Isaiah. Having seen all this, he knew he was done for. Isaiah said, “Woe is me! For I am lost; for I am a man of unclean lips…for my eyes have seen the King.” (6:5) The Lord granted Isaiah to see His full majesty, the glory of the holy Trinity with unfiltered lenses. Isaiah saw the Triune God and was terrified, for he knew that he was a sinner.
The revelation of the Triune God terrified Isaiah, but it turned out to be a blessing. While he was standing there preparing to be turned into goo, an angel flew to him. He had, “in his hand a burning coal that he had taken from the altar.” (6:6) He touched Isaiah’s lips with that burning coal and said to him, “Behold, this has touched your lips; your guilt is taken away, and your sin atoned for.” (6:7) Though the revelation of the Triune God was initially terrifying to Isaiah, it turned out to be a blessing for him. Now, he knew God (and himself) correctly. Isaiah was right when he confessed himself a sinner; and the conclusion he reached about what he deserved from God was also right. But, the almighty and eternal, glorious Trinity revealed Himself to Isaiah not to destroy him but to forgive him. And Isaiah had that forgiveness, which he would go on to preach about for many years.
In our text, the prophet Isaiah received a vision of the heavenly throne room, where he got to behold the glory of the holy Trinity with his own eyes. To him that was a terrifying thing – and he wasn’t totally wrong; the sinner in the presence of almighty God can be a scary thing. Sometimes we treat the doctrine of the Trinity as if it’s just as terrifying. But, you know what? I think we should embrace it and hold it fast, especially in these dark and latter days, where no one seems to know what’s going on in the world. According to the goodness of His mercy, our Lord has revealed Himself to us and has granted us to know Him in truth. But, to embrace the doctrine of the Trinity, we must first know what it is.
It’s true, you won’t find the word “Trinity” in the Bible; neither will you find the word “Lutheran.” Just because a word doesn’t occur, doesn’t mean the teaching implied by it or the sense isn’t there. For example, David says in Psalm 16, “You will not abandon my soul to Sheol, or let Your Holy One see corruption.” (16:10) Nowhere in that verse does David say the specific words “Jesus” or “Resurrection,” and yet that is in fact what the verse is about. The word Trinity is the word the Church uses to describe the way God reveals Himself to us throughout the Scriptures. He reveals Himself to us as three persons: the Father, Son and Holy Spirit. The Scriptures are also clear that there is only one God. That’s the way Jesus speaks. He speaks about the Father as God, Himself as God, and the Spirit as God – all three are together one God. No amount of mental gymnastics is going to find a way to understand this. It must simply be believed.
I said the doctrine of the Trinity isn’t a burden, it’s a blessing, because by it we know God correctly. We know the greatness of His love for us when we confess God the Father, who made us, provides for us, and defends us against all evil. We see this love put into action when we confess our faith in God in the Son, the one who, before the foundation of the world, elected to take on our same human flesh and die so that we might be forgiven. We see this love extended to us when God the Holy Spirit comes to us through the Word. He comes to us in our lost and sinful state, He brings us to repentance and creates faith in our hearts. This is a daily process, by which the Holy Spirit makes and keeps us holy in Christ and in the forgiveness of sins.
Sometimes we act like Isaiah in the throne room when it comes to the Trinity. We buckle at the knees and close our eyes. This would be a right reaction except for the fact that we are baptized Christians. Our Lord Jesus Christ suffered for us in the flesh and then rose again for us. We have the forgiveness of our sins. Beyond that, we have been given the blessing of knowing and being able to call upon God as He truly is. The Almighty God, the creator of all that exists has revealed Himself to you and me. And though we will not understand it this side of Eden, yet this teaching is a great blessing. God has revealed Himself as the One God in Three Persons: The Father who creates, the Son who redeems, and the Spirit who sanctifies and comforts. To Him alone be all glory, honor, and worship. Amen.