The preachers’ nightmare, Trinity Sunday. How do we explain that God is three persons and one God? It does not make sense. Simply the doctrine says: The Father is fully God, but the Father is not the Son nor the Holy Spirit. Jesus, the Son, is fully God, but the Son is not the Father nor the Holy Spirit. The Holy Spirit is fully God, but the Holy Spirit is not the Father nor the Son. Lot’s of things have been said to explain it.
Water can be ice, water or steam.
Nice try, but water can not exist as ice at the same time as steam. (I am ignoring scientific pedantry of the triple point of water here, as most who use this illustration do not mention the triple point.) Trinitarian doctrine says that God has been co-existing as Father Son and Holy Spirit from eternity in the past to eternity in the future. The ice, water, steam picture is Modalism, a hereby that says God is only one of the persons at a time, but God is, and can be experienced, as Father Son and Holy Spirit at the same time.
I am a Father, a husband and a son.
(Or Mother, wife, daughter, depending on who is talking). I am not a husband to the same person that I am a son to. God is Father Son and holy Spirit to all.
The oil loved by cyclists. Something that lubricates, penetrates and displaces water. Three functions in one oil. This does the opposite of modalism. Because although distinct in function the persons of the Trinity are also distinct.
There is the chocolate, the orange centre and the cake bit, three parts of the biscuit we experience as three and as one. But the chocolate is not fully the biscuit.
Putting it together, we have no pictures which do justice to the picture of the Trinity. When I worshipped in an Anglo-Catholic Church (I was a token Evangelical on the PCC) a phrase that was used was, “This is one of the mysteries of the faith.” Which is another way of saying, “I do not understand this either.” Which is good. We do not have to understand what is meant by Trinity, I don’t understand it. But it can be experienced. We experience God as Father and as Son and as Holy Spirit, not because there are three aspects of God, like aspects of 3in1 oil. We experience the one God as Father Son and Spirit because God is Father Son and Spirit, and each one is not part of God but fully God. That’s the important thing. Like the Jaffa Cake, taste and see that it is good.