In the context of being accused of blasphemy (on the grounds that he, a human being, had claimed to be God’s son) Jesus talks in John 10:22–42 about the nature of his relationship with God.
Although the word ‘Trinity’ does not occur in the Bible, significant New Testament references to the Father, Son, and Holy Spirit (cf. Matthew 28:18–20; 2 Cor 13:14, as well as this passage from John) gave rise to a Trinitarian notion of the divine—God is one, undivided and immutable in substance and yet lives and acts in the three persons of Father, Son, and Holy Spirit.
Once the Christian faith had become the accepted religion of the Roman Empire under Constantine in the early fourth century, and Christian art and architecture began to flourish, visual artists began to grapple in earnest with this complex dogma.
This English sixteenth-century illumination is one of the most unusual, imaginative, and striking in the wide range of Trinitarian images in the history of Christian art. While the triandric iconography (three male figures of identical appearance) was to develop as a type of Trinitarian iconography around the twelfth century, this composition is unique in its superimposition of the sun, its rays both covering and emanating from the Trinity, and pervading the whole page. While Father and Son look almost identical, so as to underscore their oneness and unity, the Holy Spirit’s body is rendered in white as a youthful figure, not uncommon in Trinitarian iconography—a pictorial attempt, it seems, to render the non-corporeal pure, dynamic, ever-alive nature of the Spirit.
The divine light both is and springs from God and shines into the world with multiple tiny angels in red, like flames, and in white, like doves—references to the Holy Spirit and to divine love. The symbols of the four Evangelists are included in each corner. The illumination thus alludes to the one God, the creator God, to God as light of the world, to divine, kingly omnipotence (the crown), as well as to the proclamation of the good news (Evangelists) and thus indirectly to the divinely-inspired church on earth.
http://www.bl.uk/catalogues/illuminatedmanuscripts/record.asp?MSID=8712&CollID=16&NStart=20215 [accessed 14 July 2018]
Thiessen, Gesa Elsbeth. 2009. ‘Images of the Trinity in Visual Art’, in Trinity and Salvation: Theological, Spiritual and Aesthetic Perspectives, ed. by Declan Marmion and Gesa Elsbeth Thiessen (Oxford: Peter Lang), pp. 119–40
22 It was the feast of the Dedication at Jerusalem; 23it was winter, and Jesus was walking in the temple, in the portico of Solomon. 24So the Jews gathered round him and said to him, “How long will you keep us in suspense? If you are the Christ, tell us plainly.” 25Jesus answered them, “I told you, and you do not believe. The works that I do in my Father’s name, they bear witness to me; 26but you do not believe, because you do not belong to my sheep. 27My sheep hear my voice, and I know them, and they follow me; 28and I give them eternal life, and they shall never perish, and no one shall snatch them out of my hand. 29My Father, who has given them to me, is greater than all, and no one is able to snatch them out of the Father’s hand. 30I and the Father are one.”
31 The Jews took up stones again to stone him. 32Jesus answered them, “I have shown you many good works from the Father; for which of these do you stone me?” 33The Jews answered him, “It is not for a good work that we stone you but for blasphemy; because you, being a man, make yourself God.” 34Jesus answered them, “Is it not written in your law, ‘I said, you are gods’? 35If he called them gods to whom the word of God came (and scripture cannot be broken), 36do you say of him whom the Father consecrated and sent into the world, ‘You are blaspheming,’ because I said, ‘I am the Son of God’? 37If I am not doing the works of my Father, then do not believe me; 38but if I do them, even though you do not believe me, believe the works, that you may know and understand that the Father is in me and I am in the Father.” 39Again they tried to arrest him, but he escaped from their hands.
40 He went away again across the Jordan to the place where John at first baptized, and there he remained. 41And many came to him; and they said, “John did no sign, but everything that John said about this man was true.” 42And many believed in him there.