For almost five hundred years, various versions of the Book of Common Prayer have referred to the celebration of the Holy Eucharist as “a sacrifice of praise and thanksgiving,” or words to that effect. All of the eucharistic prayers in our prayer book except for one include a version of this phrase, and even the one that doesn’t include it embodies the sentiment behind it. The phrase was included in part because the framers of the prayer book wanted to make sure that worshipers knew that Christ’s sacrificial death happened once for all on the cross, and was not being offered again on the altar, but instead, his death and resurrection were a full, complete satisfaction for the sins of the whole world.

It is Trinity Sunday! A day at the heart of the Christian Faith, the only day of the Christian year devoted to a doctrine rather than an event or a person because it is our most celebrated doctrine. A doctrine that represents a hard-won understanding that every generation of Christians needs to learn for themselves because it is not the sort of insight that is easily captured in sentences passed on through the generations. Faced with the Trinity, you may quite rightly feel the same way as the ancient prophet Isaiah did in today’s reading saying, “Woe is me! I am lost” (Is. 6). It calls for continual thinking and rethinking as each generation strives to add understanding to faith.

Today we celebrate the feast of Pentecost, as always fifty days after Easter; it is the feast of the Holy Spirit, and today we remember the day the disciples learned how the resurrected Christ would continue to be present with them and in them and how this would make all the difference. This language of “the Spirit” is so much a part of our Christian tradition that it shows up in nearly every prayer. It’s a language that appears less and less in our culture. The language of the Spirit is one heard mostly in Church. Why we need it is that it is a word for “depth.” St. Paul writes in one of his letters, “The letter kills, but the Spirit gives life” (2 Cor. 3:6). Spirit is a word for people who are not content just with the material surface of the world, but want more. We are constantly bombarded with images of all kinds, it is mostly all surface, sometimes very large digital surfaces that have the illusion of depth but still just present the exterior of things. If what you want is depth, if you want more than the image, if you want the Spirit, you can feel really alone and even perhaps wonder, what is wrong with me that I want more?

Up until this point, Jesus has been speaking to his disciples – comforting them, cajoling them, and coaching them about what is to come after he has returned to God the Father. But here, in chapter 17, Jesus stops talking to the disciples and begins speaking to God. The disciples, and we, are privileged to overhear one side of a conversation that is grounded in a love so powerful, it changes the world.

In these last weeks of the Easter season, our scripture readings turn toward seeing the life of Jesus (that we have been following since Christmas) in God. The reason is that for us in our day to experience the life of Jesus means receiving his Spirit with the disciples on the upcoming Feast of Pentecost and on Trinity Sunday seeking to understand how that very Spirit is both truly his and what connects us to the Source of all things. Today we witness our St. Paul standing before the renowned philosophers of ancient Athens, descendants of Socrates, Plato, and Aristotle, who taught in that very city. He preaches to them the God of Jesus Christ.

All across New England, fields are bordered by miles of old stone walls. You may have seen them out past Rte 128: walls constructed masterfully of stones laid on top of each other and fitted together with no mortar at all. They have lasted for centuries, some of them.