Knowing and confessing the Trinity in Unity

Sermon for Trinity Sunday

Romans 11:33-36  +  John 3:1-15

On this festival of the Most Holy Trinity, we confess what every true Christian confesses: that the God who reveals Himself in the Holy Bible is the only true God and the only true Savior. He is the God of both the Old and the New Testaments, the one God who reveals Himself as Father, Son, and Holy Spirit. One God who is three Persons—three distinct Persons, not one Person. One God, not three separate Gods. And, as the Athanasian and the Nicene Creed emphasize, one of those Persons also became Man for us and for salvation. He was already God, and still is God, but He took on a human nature in order to suffer and die in the place of sinful human beings, so that now we have a blood relative in one of the Three Persons of God, so that His Father has become our Father, not just because He created us, but because He has also adopted us through faith in the Son, in the Holy Spirit’s ceremony of adoption called Holy Baptism.

It’s not about understanding God or comprehending God. It’s about knowing God as He has revealed Himself in the Person of His Son. Jesus said, “This is eternal life, that they may know You, the only true God, and Jesus Christ, whom You have sent.” To know this God is to have eternal life. To not know Him is to remain in the darkness of sin and death.

So we do well to keep it simple. Trinitarian Theology isn’t hard, as long as we don’t try to cram the Trinity into our human reason. It’s simply knowing who God is, what He has done to save us, and how we receive that salvation from Him, all of which is treated in our Gospel from John chapter 3.

Nicodemus—a Pharisee, a ruler in Israel—came to Jesus at night. He was intrigued by Jesus, but still didn’t believe in Jesus as the Christ. He was still stuck in his Pharisee’s mentality: salvation by obeying the Law, salvation by good works, salvation by birthright. He rightly saw the signs and miracles Jesus did as a testimony from God that Jesus had come from God. But he still didn’t believe in Jesus as the Son of God, and so he still didn’t know God the Father, either.

Jesus told him the truth: Most assuredly, I say to you, unless one is born again, he cannot see the kingdom of God. He explained it further: Unless one is born of water and the Spirit, he cannot enter the kingdom of God. That which is born of the flesh is flesh, and that which is born of the Spirit is spirit.

The Pharisees were so proud of their birth, so proud of their heritage as Abraham’s children. They were so proud of the decent, religious, law-abiding citizens they had worked so hard to become. And Jesus tells Nicodemus, it’s all worthless. It’s all for nothing. You’ll never be good enough to see the kingdom of God, to escape death, to enter heaven. Unless you are given a new birth and become a new person, you will perish.

You see, it’s important to know who God is, but it’s really just as important to know who man is, to know who you are. Everyone, every person on earth has the same problem, the same incurable, natural, hereditary disease. One name for it is Original Sin. It has corrupted our flesh—and the soul within—beyond remedy. It’s the root cause of all unbelief and every false religion in the world. It’s at the heart of every homicide, every angry outburst, every lazy attitude, every feeling of jealousy, every act of self-service, every thought that the rest of the world really exists to serve “me.” You can’t fight it, you can’t correct it, you can’t beat it, you can’t get rid of it.

Your only hope, Jesus says, for seeing, for entering the kingdom of God, is a new birth.

How does that new birth take place? God’s Spirit has to do it—the Spirit of the Father, who, through the word of God, drives sinners to see how hopeless their condition is, how lost they are, how needy of salvation. He drives them to fear, to contrition—to mourn over their sins and over their ruin.

And then the same Spirit holds up before their eyes the image of a serpent on a pole. You remember that account, hopefully, from the book of Numbers. The Israelites were wandering through the wilderness, complaining again about God’s providence. So He sent venomous snakes into their camp. Many of them were bitten. So they were driven to fear, driven to contrition, to mourn over their sins and their ruin. And then God provided the miraculous cure: Moses was to take bronze, melt it and shape it into the form of a serpent, then put it up on a pole, so that all who were bitten could look up at it and be saved.

As Moses lifted up the serpent in the wilderness, even so must the Son of Man be lifted up, that whoever believes in Him should not perish but have eternal life. And so God the Holy Spirit, through the preaching of Christ, drives fearful, guilty sinners to look up and see God on the cross—God, the Son of God, given by God the Father as the sacrifice that atones for the world’s sins. By looking up at Him in faith, you are born again. You are recreated. You are forgiven. You have eternal life.

And to that rebirth and remission of sins, Jesus ties the Sacrament of Holy Baptism. Through Word and water, water and the Spirit, you have a tangible seal of the promised rebirth and eternal life, something visible to put your faith in, because Baptism has God’s promise of forgiveness and salvation attached to it.

It’s no wonder, then, that, when Jesus instituted Holy Baptism after His resurrection, He tied it directly to the Holy Trinity: Go therefore and make disciples of all the nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit. Because it’s this Triune God—Father, Son, and Holy Spirit—who brings about the salvation of sinners.

To confess the Holy Trinity as the only saving God and to confess faith in Him as the only way to be justified and saved from eternal condemnation comes with its own set of dangers, too. This week, we saw yet another example of the world’s hatred for this Christian confession when Bernie Sanders attacked a White House nominee because the nominee had once written that Muslims stand under God’s condemnation. “Do you believe people in the Muslim religion stand condemned?…What about Jews?” he asked. “Do they stand condemned too?… In your judgment, do you think that people who are not Christians are going to be condemned?” The nominee in question never directly answered the question, at least, not in his public testimony.

But you answered it today in the Athanasian Creed, and we must all continue to answer it, gladly and boldly, for ourselves and for the benefit of the world, both because it’s the truth, and because it’s only by hearing the truth that the sinners of this world can be brought to repentance and faith in Christ Jesus: “Whosoever will be saved, before all things it is necessary that he hold the catholic faith. Which faith except everyone do keep whole and undefiled, without doubt he shall perish everlastingly.” That catholic faith, very simply, is that we worship one God in Trinity and Trinity in Unity, and, specifically, that Jesus Christ is true God and true Man, who suffered, died, and rose again from the dead, that all who believe in Him, and only those who believe in Him, will be eternally saved. May that confession be always found in our hearts and on our lips! Amen.