Give me the tablets of your heart. I am becoming Moses for you, even if it is bold to say it. I am writing with the finger of God a new decalogue, I am writing a summary of salvation… I will baptize you, instructing you in the name of the Father and of the Son and the Holy Spirit… And you will know both by rites and by words.”

Gregory Nazianzen, Oration on Baptism, 40.45

The Byzantine Church commemorates Jesus’ Baptism in the Jordan on January 6, continuing the celebration of Christ’s manifestation to the world begun at Christmas. The central hymn of the feast explains that, in the Jordan, “worship of the Trinity was revealed” (Troparion of the Feast of Theophany). For Christians, what we gain in Baptism is not a new fact to look at, but an immersion into a mystery from which we see and learn everything. Preaching on this feast, St. Gregory Nazianzen intertwines transformation with instruction. Baptism chisels “a new decalogue” upon the tablets of the heart “through rites and words.” There is nothing new about Gregory’s teaching. It stems from the Lord himself, who ennobles ritual experience as the domain of instruction: “Go, therefore, and teach everyone, baptizing them in the name of the Father and of the Son and of the Holy Spirit” (Matthew 28:19). Christian life is immersion in lifelong learning from within the life of the Trinity, from within the Church, standing among the cloud of witnesses, the saints.

Gregory issues a call-and-response set of imperatives flowing from the creed, which the new Christians are to adopt. He asks that we believe that God made heaven and earth and all things visible and invisible. He further insists that we believe evil is not a being, but rather that it is parasitic on being, and incapable of anything on its own.

These first two injunctions ring strangely. They bring us into contact with a worldview about the universe, who created it, and who didn’t. The Lord of the Bible reigns, while evil is impotent to rule, let alone create. These are hard-won lessons about how the world works. Philosophers will deduce these principles on the far side of rational arguments. Some modern scientists will exclude these questions altogether as impossible for inquiry, since they can’t be levered out from the world of weights and measures through experiment. They seem like luxury beliefs belonging to the expert class.

These mysteries are revealed ones, public and in plain view. As Paul writes to Titus: “the saving grace of God has been revealed to all” (Titus 2:11). If public and plain, then how is this news mysterious? Christian mystery is not a withholding of information, the way we might hold back ingredients of a recipe so that it stays secret and our own. Christian mystery opens the door to the Father’s house in which there are “many mansions” that lie within, always unlocking new rooms and spaces (John 14:2).

Gregory is speaking here to adults, yet neophytes. It’s hardly kid stuff. A tutorial might be best deferred until the mind can manage. So much for infant baptism. Or is it? Lessons about the created order are best begun young, not because they are easily understood, but because they are painfully hard. God’s mysteries made manifest take a lifetime to unpack.

We shouldn’t deny the young the mysteries about how the world works any more than we should deny them a heart transplant. We don’t count the costs when a child’s life is on the line. It is worth cracking the sternum to carry out the surgery or crowdsourcing the funding when insurance falls short. Nor would we deny the lifetime of care required to stem complications or beat back the body’s rejection of the very thing it needs. The prophets promise us a heart of flesh, soft enough for the Lord to scratch his law upon it and his spirit to dwell inside (Ezekiel 11:19; Jeremiah 31:33). The Christian vision of the world begins with the new heart received at the birth of Baptism and it belongs to the Church to keep us healthy and childlike. It is, of course, “out of the mouths of babes and infants” that “God has fashioned perfect praise” (Psalm 8:2). Gratitude for parents, let alone praise before the Creator, is a learned habit. To be childlike entails a lifetime of dependency. Sacraments happen to us; we don’t do them to ourselves. We are bathed, we are forgiven, we are anointed, we are fed.

Though Baptism delivers on the prophetic promise of a new heart, we sinners suffer from calcified intellects and misfired affects. To repair these wounds, the Church feeds our imaginations back to health with the same prescription as Gregory gave: words and ritual. At the beginning of the Gospels, Jesus submits to the hand of the Baptist and submerges his head beneath the water. The entirety of the Scriptures lends a hand to narrate what exactly is going on with this experience. John the Baptist points to Jesus with words of prophecy: “Behold the Lamb of God who takes away the sins of the world” (John 1:29; Isaiah 53:7). The Father himself rips the skies in two, hymning the Psalm, “This is my beloved Son in whom my favor rests” (Matthew 3:17; Psalm 2:7).

The Church’s liturgy collects the psalms to sing out the cosmic nature of the experience: “The Jordan turns back on its course” when it sees the word of God, “the Lord’s voice” coming to rest on the “immensity of the waters” (Psalm 113:5; 28:3, LXX). One has to stretch the imagination to conceive of a river trembling and rerouting, as it “beholds the fire of the Godhead coming down upon it and entering it in the flesh” (Great Blessing of Water, Sophronius of Jerusalem). In all the drama of the Theophany celebration, the service ends by whacking the faithful with holy water, indiscriminately and liberally, both young and old. Everyone feels like a kid again, right where the Lord wants us—so that these new hearts can be caught by and taught by his mysteries.