The Easter season begins with the celebration of the resurrection of Jesus from the grave, and it ends with Trinity Sunday. The resurrection is concrete and specific, something that even children can relate to and understand. Easter eggs and baby chicks speak of new life. We celebrate Easter with the singing of exuberant hymns—“Up from the grave He arose!”—and churches decorated with lilies. However, in contrast to the resurrection, the doctrine of the Trinity is abstract, impossible to understand we fear, and something best left to theologians who like to speculate about things such as how 1 + 1 + 1 add up to 1, something about as practical as the question of how many angels can dance on the head of a pin. Besides “Holy, Holy, Holy,” how many hymns about the Trinity can the average churchgoer bring to mind?

I would suggest rather that the resurrection and the Trinity are the two most important doctrines of the Christian faith, both belong together, and both are imminently practical. Without either one of them, Christianity would collapse. If Jesus had not risen from the dead on the first Easter Sunday, there would have been no people called Christians. If God were not Trinity, Jesus would not have risen from the dead. The resurrection is about what God has done. The Trinity is about who God is. We know who God is from what he has done. We understand the meaning of what God has done when we understand who God is.

The Christian God is a God who acts, a God who is known by what he has done. We see that in this morning’s Old Testament readings. In the Exodus reading, the account of God’s appearance to Moses in the burning bush, we have the most fundamental account of God’s identity as known by Israel. Who is this God? This God tells Moses that is he is the God of Abraham, of Isaac, of Jacob. This God is also the one who will lead Israel out of bondage from Egypt, into the Promised Land. And so this God became associated with a particular people. This God is the God of Israel because he has delivered Israel from slavery. And this God has a name. A few verses after the passage we have read this morning, God tells Moses that his name is “I am who I am.” “Tell the people that I Am has sent you. The LORD, the God of your fathers, the God of Isaac, and the God of Jacob has sent you.” What does it mean when this God tells Moses that his name is I am Who I am? Some modern biblical scholars think it means that God simply refused to tell Moses who he was, but the Church Fathers and the Medieval theologians said it meant that God is Being. God is the One Who Is, and who always is.

In the second reading, we find a further description of the biblical God. This God is the One who creates everything that is. “The LORD has made the world so sure that it cannot be moved.” Of course, scientists now tell us that the world moves, but the point is still the same. God is from everlasting. God always is and always has been. The world is because the God who always is has made it. And the world is good because God is good, and God has made it good. As the writer of Genesis said, “God saw everything that he had made, and behold, it was very good.” The LORD is King or ruler over the world because he made it, and his Word is sure and to be trusted because he is more powerful than that which he has made. If the world is stable, then God’s Word is more stable. If the LORD is powerful enough to bring the world into being, then the LORD is powerful enough to bring his Word to pass. His promises can be trusted.

These are the central elements of the Hebrew understanding of God. God is the One who exists necessarily, and who always is. God is the One who created the world, and so God is Lord of the World. The creation is good because the God who made it is good. God has delivered Israel from slavery, and so God is Israel’s God. God has spoken his Word to Israel, and this Word can be trusted.

And there is an additional element that came to be added toward the end of the Old Testament period. Just as God had created the world, and God had delivered Israel, so God has a future plan for the world he had created. God was going to bring the world he had created to a completion—a re-creation— in which God would become the God not only of Israel, but of the whole world, and of all peoples, and in that new re-created world, God was going to deliver not only Israel, but all of creation, from all the suffering, pain, and evil that have marred this world that was originally created good.

In the New Testament writings, all of these elements of Israel’s understanding of God continued to be embraced, but something else is now known about the God who delivered Israel, because this God has done something new. In the New Testament, God is not only the One who created the world and delivered Israel from bondage. God is also the One who raised Jesus of Nazareth from the dead. That God raised Jesus from the dead tells us something new, not only about what God has done, but about who God is.

Jesus’ resurrection cannot be understood apart from what Jesus did and what Jesus said. And Jesus brought a new understanding of God. Where Israel’s prophets had spoken of bringing a Word from God, Jesus spoke his own Word with the very authority of God. Where the prophet said, “Thus says the Lord,” Jesus said, “Truly, Truly, I say unto you.”

Jesus also spoke about God and to God in a unique way. The New Testament scholar, Joachim Jeremias summed this up by saying, “For Judaism, God was primarily the Lord . . . for the disciples of Jesus, God is the Father.” It is true that there are a few instances in the OT where God is referred to as the Father of the nation, and sometimes as the Father of the King. But Jesus spoke of God as his own Father, and of himself as the Father’s Son. Biblical scholars have made much of the fact that although the NT is written in Greek, the one word that Jesus spoke that has been preserved in the original Aramaic that Jesus spoke is the word “Abba,” which is a familiar Aramaic word for “Father.” In a passage that shocks some modern biblical scholars, Jesus said, “All things have been handed over to me by my Father, and no one knows the Son except the Father, and no one knows the Father except the Son and anyone to whom the Son chooses to reveal him.” Matt 11:27. In the Lord’s Prayer, the prayer familiar to all Christians, Jesus taught his followers to pray “Our Father” because he had first called God his Father.

Jesus also spoke about his mission. He spoke of being sent to the lost sheep of Israel He said that those who accepted him accepted the Father who sent him. He said that he had come to seek and to save the lost, to call sinners to repentance, not the righteous. He said that he had come to serve and to give his life as a ransom. This notion that Jesus is the Son who has been sent with a special mission from his Father appears in that familiar verse in this morning’s gospel reading: “For God so loved the world that he gave his only Son, that whoever believes in him should not perish but have eternal life. For God did not send the Son to condemn the world, but in order that the world might be saved through him.” Jn 3:16-17.

So in light of the special authority Jesus claimed for himself, and his special relationship with God as his Father, in light of the special mission Jesus had been given, not simply to provide an example, but to deliver sinners from their sins, in light of God’s having put his own stamp of approval on that mission by having raised Jesus from the dead, it is not enough simply to think of Jesus as another good man among many. His own identity was shaped in a special way with the relationship with the God he called Father, the Father who had sent him as his Son.

After Jesus’ resurrection, the New Testament writers began to speak of God in a new way. They began to ransack the Old Testament for language that had first applied to the God who had created the world and who had redeemed Israel, and now applied it to Jesus. So where “LORD” was the characteristic way in which God was understood in the Old Testament, so now Jesus was called Lord. As Isaiah had said that every knee would bow to God and every tongue swear him allegiance, so Paul says in Phillippians that at the name of Jesus every knee will bow and every tongue confess that Jesus Christ is Lord. As Jesus had called God his Father, so now the characteristic way for Christians to address God is as Father, and Jesus is called not only Christ (or Messiah), and Lord, but also the Son of God. Where the Old Testament had described God as Creator, the New Testament writers now said that God had created the universe through his Son. Where the Old Testament had said that the God who is King would eventually bring the world to salvation and re-creation, now the New Testament writers said that Jesus would return in glory and set up his Kingdom. Where Jesus had spoken of being sent by his Father, writers like Paul and the writer of the Gospel of John spoke of Jesus as having existed with the Father from all eternity, before his Father sent him.

The New Testament writers were conscious of a third way in which God was known after the resurrection of Jesus. If Jesus’ mission had been to bring about a new relationship between God and humanity, and if his crucifixion and resurrection had made that possible, then now was the time during which that new relationship had begun to be lived out. Certainly the new earth did not yet exist, but already among the followers of Jesus there were hints and signs that this new redeemed world had already begun, that it was not only on its way, but already beginning to be. Jesus had gathered a new people of God, growing from his twelve apostles who represented the twelve tribes of Israel, and that community was now the Church. Though the earthly Jesus was no longer physically present in the sense that he could be touched and seen, yet the risen Jesus was not completely absent either. There were many ways in which these early followers of Jesus spoke of his continuing presence in his Church. They spoke of the waters of baptism as bringing about a new birth in which the baptized were united with Jesus in his death and resurrection. They spoke about the bread and wine of the eucharist as the Body and Blood of the risen Christ. They spoke of their own gathered community, the Church, as the body of Christ. They spoke about grace and forgiveness of sins. But all of these things were made possible because after the resurrection of Jesus, God was in their midst in a new way as the One whom they called the Holy Spirit, and who made the risen Jesus to be present even while he could not be seen or touched. And so in today’s epistle, we see Paul adopting the language that Jesus had used to speak of God as his Father, and of himself as God’s Son, to speak of the way in which the Spirit enables us to share in the very life that flows between Father and Son. Paul says, “When we cry, ‘Abba! Father!’ it is the Spirit himself bearing witness with our spirit that we are children of God.” Similarly in this morning’s gospel, Jesus speaks of the way in which faith and baptism bring us into the life of the Spirit: “Unless one is born of water and the Spirit, he cannot enter the kingdom of God. . . as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life.”

These then were the beginnings of the Christian doctrine of the Trinity. For Christians came to realize that if God had revealed himself to his people as Father, Son, and Holy Spirit, in Gods’ creation of the world and his redemption of Israel, in Jesus’ mission, life, death, and resurrection, and in the Spirit’s presence in the Church, then God had to be Father, Son, and Holy Spirit in himself. If the relationship between Jesus and the God he called Father was a true revelation of who God really is, then that relation has to be part of God’s very being from all eternity. The love between Father and Son that led the Son to give himself to the Father all the way to death on a cross, and led to the Father raising the Son from death was a playing out of a love between Father and Son within the very heart of God that had always been. The mission that the Son lived out in history reflects an eternal mission in which from all eternity the Father begets the Son. The loving obedience in which the Son obeys his Father even to death, reflects an eternal giving back of the life that the Son receives from the Father from all eternity. If the Spirit truly unites us to the Risen Son so that although Jesus is bodily absent, yet through physical things like water, we can share in his death and resurrection, and through bread and wine the risen Jesus can come to us in his body and blood, this can only be because the Spirit who brings the risen Jesus to us, is himself already one with God as part of the eternal giving and receiving from all eternity that is the Father and the Son. Or, rather, as St. Augustine suggested, the Spirit is himself the Love that both flows between the Father and Son, and unites them together from all eternity.

Is the doctrine of the Trinity abstract? If by the doctrine of the Trinity we mean the statement that God is three persons in one substance, which is the official doctrine, that is, of course, abstract. But three persons in one substance is simply the shorthand formula we use to describe the Trinity. The Trinity is not a formula, but the Father, the Son, and the Holy Spirit living and sharing one life as God from all eternity. To draw a comparison: Is water abstract? The formula for water is H2O, and that is certainly abstract, although a physicist or chemist sometimes can find the formula quite helpful, indeed necessary. However, when we come in from the outside on a hot muggy day, and turn on the tap to refresh ourselves with liquid refreshment, there is nothing abstract about it. In the same way, the formula for the Trinity is beyond the reach not only of the average person, but even of the most profound theologian. Nonetheless, the way to understand the Trinity is the same way in which we would understand that glass of water on a hot day. If the Trinity is the eternal life and the eternal love between Father, Son, and Holy Spirit, and God has shared that life with us first by making us, and then by redeeming us, and now by being present among us, the way to know the Trinity is by entering into that eternal communion for ourselves, by being united with Christ in his death and resurrection through the waters of baptism, by becoming one with Christ through sharing in his body and blood. “Taste and See that the Lord is good,” says the Psalmist. “If anyone thirsts,” says Jesus in John’s gospel, “let him come to me and drink” “I am the Bread of Life,” says Jesus, “whoever comes to me shall not hunger, and whoever believes in me shall never thirst.”

So, far from being an abstraction, the doctrine of the Trinity is a most practical doctrine. Our entire Christian life is made possible because God is Trinity. We exist because God the Father created us. We are re-created in God’s image as we come to share in the resurrection of Jesus Christ. We are united to the risen Christ because God’s Holy Spirit lives within us. Our prayers, our worship, our love of God and neighbor, all are made possible because the God who is Father, Son, and Holy Spirit, has come to share his life as Trinity with us. Finally, God’s ultimate goal for us will be our own resurrection on the last day, when we will be changed to see God as he is, when the union with the Father, the Son, and the Holy Spirit which we share now to a limited extent, will become fully realized, and we will enter as fully as possible as it is for human beings to enter into the harmonious unity of God’s life as Trinity.

Batter my heart, three-person’d God ; for you
As yet but knock ; breathe, shine, and seek to mend ;
That I may rise, and stand, o’erthrow me, and bend
Your force, to break, blow, burn, and make me new.
I, like an usurp’d town, to another due,
Labour to admit you, but O, to no end.
Reason, your viceroy in me, me should defend,
But is captived, and proves weak or untrue.
Yet dearly I love you, and would be loved fain,
But am betroth’d unto your enemy ;
Divorce me, untie, or break that knot again,
Take me to you, imprison me, for I,
Except you enthrall me, never shall be free,
Nor ever chaste, except you ravish me.

John Donne