As Christians we worship One God, Father, Son, and Holy Spirit: they are not three Gods, but one God. That the three persons of the Trinity are one God is itself a mystery. The mystery of God’s very self: a Trinity of Persons, consubstantial, co-equal and co-eternal. We know God most fully in the person of Jesus Christ, the Incarnate Word of God, born of the Virgin Mary, who died upon the Cross for our sins, and was raised to New Life at Easter, who sent the Holy Spirit at Pentecost. In Christ God discloses who and what he is, we know Him as someone who pours out LOVE, who is interested in reconciliation. 

We celebrate the Feast of the Holy Trinity today because in 1334 Pope John XXII decided that on the Sunday after Pentecost the Western Church would celebrate the mystery of the Trinity. It was already a popular feast, and had been kept in some form since the triumph of Orthodoxy over the followers of Arius in the 4th century. Nearly two hundred years before the Pope ordered that the feast be kept by the Universal Church, Thomas Becket was consecrated a bishop on this day, and kept the feast. Its popularity in the British Isles is shown by the fact that in the Prayerbook we number the Sundays between now and Advent not ‘after Pentecost’ but ‘after Trinity’. It defines the majority of the liturgical year for us.

This morning, at the very beginning of our service, the following words were said, ‘In the name of the Father, and of the Son, and of the Holy Spirit.’ We said, ‘Amen’ to signify our assent and many Christians make the sign of the Cross as the words are said. At the end of the Eucharist I, as a priest, will pray that God will bless you as I invoke the name of the Trinity and make the sign of the Cross. These words and gestures are not random, or the result of a whim, but are part of our tradition of worship as Christians. This is how we express and declare our faith in God the Father, Son, and Holy Spirit; through our words and actions. We say these words because they express our faith.These help us to reinforce what we believe and help us to live out our faith.We make the sign of the Cross, the thing that saves us, the centre of our faith.

In this morning’s Gospel we see Jesus’ encounter with Nicodemus, and after a discussion of baptism, and the new life which God in Christ offers Jesus says, ‘And as Moses lifted up the Serpent in the wilderness so must the Son of Man be lifted up, that whoever believes in him may have eternal life’ (Jn 3:14-15 ESV). Jesus refers to an incident in the Book of Numbers: ‘Then the Lord sent fiery serpents among the people, and they bit the people, so that many people of Israel died. And the people came to Moses and said, “We have sinned, for we have spoken against the Lord and against you. Pray to the Lord, that he take away the serpents from us.” So Moses prayed for the people. And the Lord said to Moses, “Make a fiery serpent and set it on a pole, and everyone who is bitten, when he sees it, shall live.” So Moses made a bronze serpent and set it on a pole. And if a serpent bit anyone, he would look at the bronze serpent and live.’ (Numbers 21:6-9 ESV) Jesus uses this story to help us to understand His coming Crucifixion. It will save whoever believes in Him, it is the supreme demonstration of HOW MUCH God loves us. The Love of God is such that He gave His only Son ‘that whoever believes in him should not perish but have eternal life. For God sent the Son into the world, not to condemn the world, but that the world might be saved through him.’ (Jn 3:16-17 ESV). God does not send Jesus to condemn humanity for its sin, its disobedience, but to save humanity THROUGH LOVE, through selfless, sacrificial, redemptive LOVE: dying for us, bearing the burden of our sin, and reconciling us to God, and each other, making the Kingdom of God a reality, and so that we can have a relationship with God, and each other which is rooted in LOVE, a love which is the very nature of God, how God is. 

The Love of God sees Jesus take flesh by the power of the Holy Spirit, to be born of the Blessed Virgin Mary, preach repentance and the nearness of the Kingdom of God, and die for us on the Cross. Then he rose again, ascended, sent the Holy Spirit to us at Pentecost, and promised to come again as our Judge. Fellowship, or Communion is what the persons of the Trinity — the Father, the Son and the Holy Spirit — have between each other, and which we the Church are invited to share, with them and each other. It is the imparting of the grace, the undeserved kindness of God, of a God who dies to give us LIFE with Him forever. In the act of Holy Communion we are fed by Christ with the Body and Blood of Christ, so that we might share in the divine life here on earth, and share it with others.

We can do this because we have been baptised. In this morning’s Gospel Jesus tells Nicodemus, ‘Truly, truly, I say to you unless one is born of water and the Spirit, he cannot enter the kingdom of God.’ (Jn 3:5 ESV) In our baptism we share in Christ’s death and resurrection, we put on Christ, we are clothed with Him, we become part of His Body, the Church. We are re-born, born again. It is how we enter the Church; how we are saved. It defines us as Christians — we are baptised in the name of the God who saves us, and we are His.

Jews, Muslims, Jehovah’s Witnesses, Mormons and others cannot accept the fact that as Christians we say that we do not worship three Gods, but One God. They cannot accept that we believe that the Son is God, not less than the Father, likewise the Holy Spirit, and yet there are not three Gods but one God. These are not manifestations, but persons which share the same divine essence and yet they are distinct. The Father uncreated; the Son begotten; the Spirit proceeding. It is why we stand up and state our beliefs when we worship God. It matters. We do it regardless of the cost. Simply believing the Christian faith and declaring it publicly can lead to imprisonment or death in some countries around the world today. It is a serious business being a Christian, and wonderful, because we follow a God who shows that His very nature is LOVE. We are filled with that love, and share it with others.

Our faith matters. It can change lives. It can change the world, one soul at a time. It isn’t simply a private concern, something to be brought out for an hour on a Sunday morning and then hid away politely. It is the most important thing there is. It is something to fill us with joy. It is something that we should share with others, so that they might believe and give glory to God the Father, God the Son, and God the Holy Spirit, to whom be ascribed as is most right and just, all might, majesty, glory, dominion, and power, now and forever.