The Holy Trinity
Sunday, June 15, 2014
“The Living Room of Peter’s Pentecost Sermon” (Acts 2:14a, 22-36)
Today is the Feast of the Holy Trinity. On this day we sing hymns emphasizing the Trinitarian nature of the one true God, Father, Son, and Holy Spirit. On this day we say that really long creed with the funny name, the Athanasian Creed, which goes into the most detail on the relationship of the three persons in the Trinity. Today we are celebrating, not some dry doctrine with no connection to life, no, rather we are celebrating a living reality–the reality of who God is, as he is, as he has acted to save us and give us life, as he has revealed himself to us in Holy Scripture. Today we are confessing the truth of the Holy Trinity, over against all heretics that have arisen in history, from the Arians of the fourth century to the Mormons and Jehovah’s Witnesses of our day. The living reality of the triune God and the true and saving doctrine concerning the same–that’s what this Holy Trinity festival is all about.
Now there is much about the mystery of the Holy Trinity that is hard for us to understand. How can there be three persons and yet only one God? How can this triune God have always been, uncreated, from eternity? I suppose that if we could fully understand God, we would have to be God!
But while there is much that remains hidden to us mortal creatures, there is also much that has been revealed. God wants us to know him, in a living, vital relationship, and to know what we need to know about him in order to be saved. And that’s where our Scripture readings today come in.
Today I want us to focus on one of the readings, the one from Acts chapter 2. This reading picks up where our reading from last week left off. It’s Peter’s Pentecost sermon. Last week we heard the first part of his sermon, the introduction, what I called the “front porch” of his sermon. Today we continue with the main part of that sermon, what I’ll call “The Living Room of Peter’s Pentecost Sermon.”