Be joyful in HOPE,
patient in affliction,
faithful in prayer.
Share with the Lord’s
people who are in need.
Romans 12:12-13

Trinity Sunday – 2023

On Trinity Sunday we began a series of catechism sermons on the Ten Commandments.


Sermon Text, Deuteronomy 5:1-6, 6:4-7. And Moses called all Israel, and said to them: “Hear, O Israel, the statutes and judgments which I speak in your hearing today, that you may learn them and be careful to observe them. The LORD our God made a covenant with us in Horeb. The LORD did not make this covenant with our fathers, but with us, those who are here today, all of us who are alive. The LORD talked with you face to face on the mountain from the midst of the fire. I stood between the LORD and you at that time, to declare to you the word of the LORD; for you were afraid because of the fire, and you did not go up the mountain. He said: ‘I am the LORD your God who brought you out of the land of Egypt, out of the house of bondage.’ … Hear, O Israel: The LORD our God, the LORD is one! You shall love the LORD your God with all your heart, with all your soul, and with all your strength. And these words which I command you today shall be in your heart. You shall teach them diligently to your children, and shall talk of them when you sit in your house, when you walk by the way, when you lie down, and when you rise up.”

Lord, this is Your Word and these are Your words. Sanctify us by the truth. Your Word is truth. Eternal praise be to You, O Father, Son, and Holy Spirit! Amen.

Dear people loved and purchased by God to be His own: Grace to you and peace from God the Father and our Lord Jesus Christ. Amen.

Trinity Sunday is a good time to begin a series of sermons on the Ten Commandments. For the Ten Commandments have a lot to do with who the true God is. It’s not any of the false gods of other religions, that were able to put God’s law in man’s conscience. Only the true God did that.

The Triune God is there in the Old Testament too. We see signs of the Trinity, when God says “We” or “Us” – like He does in Genesis 1, when He says: “Let Us make man in Our image,” or in Genesis 11 at the tower of Babel, when God says, “Let Us go down and there confuse their language.”

There’s another sign in our text. When “LORD” is in all capital letters, it’s connected to the story of Moses and the burning bush. God said His name was “I Am Who I Am.” Jesus calls Himself the I Am, showing that He’s the God of the burning bush. God in the burning bush is the Triune God, so when we see “LORD” in all capitals like this, we’re to think: “Triune God.”

Notice here in Deuteronomy 5: this holy name of God is in every verse, from chapter 5 verse 2 through verse 6, where He says: “I am the LORD your God who brought you out of the land of Egypt, out of the house of bondage.” Here Moses is speaking to the children of Israel who are about to enter the Promised Land. These are actually the children of the people who were in the exodus. This is after 40 years of wandering. Moses recites the words the way God said them on Mount Sinai.

This brings us to the Ten Commandments. Did you know that the Ten Commandments don’t actually begin: “You shall have no other gods” (the 1st Commandment)? Instead, they begin: “I am the LORD your God …”

God was talking to the Israelites whom Moses brought out of Egypt. They were individuals, men and women and children with names, who were of this clan from this tribe. The Triune God says to them as an identifiable group and as individual persons: “I am your God.”

But because the Ten Commandments follow this, and they are the moral law that applies to all people of all times and places, this is something God was saying to the next generation, their children, here in Deuteronomy 5; and which He says to all people, and every person: “I am *your* God.”

On Trinity Sunday we should especially hear this personal part. He isn’t just the one true God who exists. He is the one true God who exists for you. He intends to have a claim over you, to be available to you, to do His works for you. In this way He belongs to you. And then it works the other way too: you belong to Him. He is yours and you are His.

It’s even this way in the second-to-last chapter of Revelation. It says: “God Himself will be with them and be their God.” And then God says of “He who overcomes”: “I will be his God and he shall be My son.”

This sounds so good. But there’s a disconnect. It is by faith that I belong to Him; but it isn’t disconnected from the commandments. However, the disconnect happens all the time: people say they believe but live however they want. They’d be shocked at what our Lutheran Confessions that say: “The faith of which we speak exists in repentance. Therefore, it cannot exist in people who live by the flesh, who take pleasure in their own lusts and obey them.” (Apol. IV, para. 142) It’s shocking because of how we disconnect these things.

But what the giving of the Law on Mt. Sinai shows is that keeping His commandments is an essential part of belonging to Him, being His people.

Right before God gave Moses the Law, He had this message for the children of Israel: “You have seen what I did to the Egyptians, and how I bore you on eagles’ wings and brought you to Myself. Now therefore, if you will indeed obey My voice and keep My covenant, then you shall be a special treasure to Me above all people; for the earth is Mine” (Ex 19:4-5).

Did you hear the “if-then” language in this covenant God made with them? Yet we know we can’t come into God’s favor by our obedience to the Law. What do we do with this? Well, what God was saying in a simple way – in the words, “I am the Lord your God, who brought you out of Egypt,” followed immediately by the commandments – is that the fact that they are His people would be shown by walking in His commands.

Our problem today isn’t usually that we’re trying to be in His favor by doing the works of the Law. It’s that we think we can still be in His favor, and not even care about His commands, only about doing what will please ourselves or live up to the expectations of others. The problem is when we disconnect our faith in the Gospel from our doings and life.

The Ten Commandments aren’t just a bunch of do’s and don’ts. They don’t come from a God who just wants to order you around. He isn’t getting His jollies seeing if you’ll pass or fail. First comes the loving relationship that He speaks into existence. He declares that we are His people, we belong to Him, He’s the Lord our God. Then comes the “you shall … you shall not,” as if to say: “This is what it looks like to belong to Him.”

When you sin, you say that your will is more important than His. You make it look like you don’t belong to Him but that you are your own god, and as you seem to be OK living without Him, then the Law says: OK, picture an eternity without Him. This should terrify you! The Law’s chief use is to produce this terror, and sorrow over your sin – so that you repent.

Then you’re ready to hear the Gospel with new ears: that Christ came to do the Law for you, and He takes your sins from you and gives you His perfect righteousness and obedience that counts for you. By God’s grace, you do belong to Him. There’s no if-then. You belong to Him by Jesus’ doing, as the Holy Spirit gives you faith in Him.

The words from Deuteronomy 6:4, “Hear, O Israel: The LORD our God, the LORD is one!” do not just confess that God is one God. This is confessing faith in the Gospel: that in spite of breaking the commandments, He is “the LORD *our* God,” we still belong to Him, by faith.

Then the Law becomes what you do in the way God intends: not for it to be a burden, but that you live in the Law, that it guides you in how to live as a Christian: to “love the LORD your God with all your heart, with all your soul, and with all your strength.” These “words,” the Ten Commandments, will then be held “in your heart,” to accompany you in your house, on the roadway, going to bed and waking up with them.

For this we need a loving Father, Jesus and His blood, and the Holy Spirit not only comforting us with His grace but leading us by His Word. And this is who we have: “the LORD our God.” Amen!