The calendar of the church year begins with the season of Advent, when we reach back into the Old Testament to look at the prophetic word that announced Christ’s coming centuries before He arrived on the scene. We hear that One is going to come into the world to save lost and fallen humanity. Isaiah the prophet, speaking 730 years before Jesus’ brith puts it this way: For unto us a child is born, Unto us a Son is given. And his name shall be called “Mighty God,” “Everlasting Father,” “the Prince of Peace.

Then comes the celebration of our Lord’s birth at Christmas time. And we celebrate the great mystery of our faith: God became man for us!

Then in the season of Epiphany we celebrate his being manifested not only as the long-awaited Messiah of the Jews, but as the Lord of the whole earth.

And then we move to the last week in Jesus’ life. On Palm Sunday we celebrate Jesus’ triumphal entry into the City of Jerusalem: Hosanna to the Son of David. Blessed is he who comes in the name of the Lord! And during that week we walk through the events of that last week. On Good Friday we stand at the foot of the cross and watch him die.

And then on the third day, we come with the three women to the tomb and see that it’s empty. “He is not here!” is the message of the angel. “He is risen, just as he said!”

And then that 40-day period of time between the resurrection and the ascension of Jesus in which Jesus instructed his disciples concerning the Kingdom of God, and told them not to depart from Jerusalem until they had been baptized in the Holy Spirit.
And then, barely 10 days after his Ascension to the right hand of the Father, we observe the great outpouring of the Holy Spirit on Pentecost, which we celebrated last Sunday.

But today in the church year is called “Trinity Sunday.” And the reason for its location at this place is very clear. Now the fullness of the revelation of the God whom we worship has been given to us. A God as “Father.” God as saving “Son.” And God as “Holy Spirit.”
The doctrine of the Trinity cuts a window into the awesome invisible nature and character of God Almighty. It cuts a window into his very heart. And the window is triangular.

To live a fully Christian life is to live in the light flowing from that triangular window into our very souls. To live in the reality, the experience reality of God as Father, and as Son, and as Holy Spirit.

Your Brother in Christ,

Marshall