We always start our prayers by making the Sign of the Cross to remind us of the greatest mystery of our faith: the mystery of the Most Holy Trinity. It’s not a mystery as seen on TV where CSI checks a crime scene, fingerprints and DNA evidence, witnesses: it’s something so big that it doesn’t fit into our head. We couldn’t have ever figured out on our own that God was Father, Son, and Holy Spirit. God revealed himself to us as the Most Holy Trinity. Jesus came and said he was God’s Son, and that meant God was his Father. And Jesus promised to send his Spirit after he ascended into Heaven, so the Holy Spirit was God as well. This is something so mysterious that we believe it because Our Lord taught it to us and we believe in him.
Moses in today’s First Reading reminds the Israelites, as he reminds us, that this great mystery of faith is totally God’s initiative. God chose to reveal himself to us as he is: the one true God. At the time of the Israelites, every nation had its god, and they all believed along with the big wars of nations there were always big wars between the gods as well, big gods and little gods: a whole pantheon of gods. God revealed himself to the Israelites as the one and only God, and he showed it by going into Egypt, that had, according to the Egyptians, the most powerful gods, and he took Israel out of Egypt showing his power and made them into a nation with him as their God.
The nation of Israel showed the world that not only was their God the most powerful God, he was the One and Only God. That revelation was a preparation so that one day God would send his Son and reveal to us that not only was there One God alone, which was what the Israelites believed, but that God is the Trinity: Father, Son, and Holy Spirit. It’s the greatest mystery of our faith.
In today’s Second Reading Paul describes what happens to us at Baptism. On the day you were baptized, a minister poured water on your head (or immersed you in the water) three times, and each time he poured it he said “I baptize you in the name of the Father … and of the Son … and of the Holy Spirit.” In that moment you received the Holy Spirit, who made you into an adopted son of God. God became your Father. Jesus became more than your best friends: he became your big brother. The Holy Spirit was poured into your heart so you’d call God Abba—“Daddy!” Whenever we start our prayers, we remember this day of our baptism by making the Sign of the Cross and remembering the Holy Trinity and how God came into our hearts through our baptism.
Near the end of today’s Gospel Our Lord tells the disciples to go out and baptize everyone in the name of the Father and of the Son and of the Holy Spirit, but it also says the disciples “doubted.” “Doubted” is translated from a Greek word used only one other time in the Bible: when Our Lord pulls Peter out of the water into which he was sinking: “O man of little faith, why did you doubt?” (Matthew 14:31). Peter stepped out onto the water with the faith he could muster but was overwhelmed. The Eleven in this moment of “doubt” are about to witness the Risen Lord’s Ascension; they don’t know what’s going to happen next. In other accounts of the Ascension from their questions they think what we call today the Second Coming was going to happen then and there.
The mystery of God is what we believe, and it is what we, as believers, share. We may not completely understand the Most Holy Trinity, but we believe. Everything we do as believers we do in the name of the Father, the Son, and the Holy Spirit. The Lord reminded the Eleven, and he reminds us, that it is in the power of the Most Holy Trinity and counting on his presence that we spread the Gospel and baptize. There’s no reason to doubt.
Thank each Person of the Most Holy Trinity this week. Thank God the Father for creating us and revealing himself to Israel as the One True God. Thank God the Son for obeying his Father in Heaven and coming down and becoming man to show us that God was Our Father and enabling us to become his adopted children. Thank the Holy Spirit for transforming us into God’s adopted children and for bringing the Holy Trinity into our hearts and helping us to understand and live this great mystery of our faith.
Readings: Deuteronomy 4:32–34, 39–40; Psalm 33:4–6, 9, 18–20, 22; Romans 8:14–17; Matthew 28:16–20. See also Solemnity of the Most Holy Trinity.