The Holy Ghost proceeding from the Father and the Son in a 15th century French altarpiece
Russian icon of the Old Testament Trinity, Andrey Rublev c.1400
The Three Persons have the same face, emphasizing their unity.
Holy Trinity by Sandro Botticelli, 1491-1493
with St. Mary Magdalene and St. John the Baptist (patron saint of Florence)
The Trinity in Glory, Titian, c. 1552-1554
Adoration of the Holy Trinity, Albrecht Durer, 1510
Attacks on the Holy Trinity remind us of a quote from Anton LaVey (Levy), founder of the Church of Satan: “Unitarians are just Satanists in evening clothes.”
(5) Tell us therefore, Jew, as you deny the Trinity, and are consequently unaware of unity, if, as you assert, God is in one person, to whom did He say: “Let us make man to our own image and likeness”? [Genesis 1:26] For if there were one person in the Godhead, He would not have said “let us make,” but “let me make.” If there were three substances he would not have used the singular “our image,” but rather “our images.” Therefore, while “let us make” asserts Trinity and “our image” indicates unity, it is clearly obvious that the essentially one God consists of three persons. [Owen J. Blum, OFM, The Fathers of the Church Mediaeval Continuation, The Letters of Peter Damian 1-30, Catholic University of America, 1998, Letter 1, pp. 37-83.]
[Moses said in Genesis 11:5] “The Lord came down to see the city and the tower that the sons of Adam were building. And shortly after that he added: “Come, let us go down and there confuse their language.” [Genesis 11:7]
(6) You see, therefore, that “the Lord came down” expresses the one divine essence; but “Come let us go down” teaches that there are three persons. [Blum, p. 41.] Also ask Abraham why when seeing three men he adored one? Thus it was written: “The Lord appeared to him in the valley of Mamre, as he sat in the entrance of his tent, while the day was growing hot”; and then he added: “When he looked up, three men appeared to him standing nearby.” [Genesis 18:1-2] Notice that although he first said:“The Lord appeared to him”; when the event was described, it was not said: “a man appeared to him,” but “three men appeared to him.” It is here clearly demonstrated that He who appeared to him is one in divine substance and is threefold in person. Abraham’s words likewise give evidence of this when he says: “Sir,” he said “if I have found favor in your sight, do not go past your servant. But let me bring a little water and wash your feet, and rest yourselves under the tree.” [Genesis 18:3-4]
(8) …The prophet Isaiah also clearly and thoroughly taught this Trinity of persons and unity of nature when he reported seeing Seraphim who cried out: “Holy, holy, holy, Lord God of Hosts.” [Isaias 6:3] To show the Trinity of persons, “holy” is pronounced three times. But to indicate that the substance of the Trinity is one, he speaks of the Lord of Hosts, and not the Lords of Hosts. [Blum, p. 42.] …
(10) Take note, then, Jew, as we page through almost all the books of your law, that we quite clearly discover the unity of the divine essence and the Trinity of persons.
excerpted from: Saint Peter Damian’s Letter 1: On the Arguments of the Jews Against the Blessed Trinity by Randy Engel, Catholic Inquistor, Volume 2, No. 2, Winter 2020, pp. 19-21.
… and the spirit of God moved over the waters.
And Jesus being baptized, forthwith came out of the water: and lo, the heavens were opened to him: and he saw the Spirit of God descending as a dove, and coming upon him. And behold a voice from heaven, saying: This is my beloved Son, in whom I am well pleased.
Going therefore, teach ye all nations; baptizing them in the name of the Father, and of the Son, and of the Holy Ghost.
These explicit New Testament references to the Holy Trinity are foreshadowed in the Old Testament.
Behold my servant, I will uphold him: my elect, my soul delighteth in him: I have given my spirit upon him, he shall bring forth judgment to the Gentiles.
Come ye near unto me, and hear this: I have not spoken in secret from the beginning: from the time before it was done, I was there, and now the Lord God hath sent me, and his spirit.
The spirit of the Lord is upon me, because the Lord hath anointed me: he hath sent me to preach to the meek, to heal the contrite of heart, and to preach a release to the captives, and deliverance to them that are shut up.
The Lord hath said to me: Thou art my son, this day have I begotten thee.
Psalm 2:7 , also quoted in the New Testament in Hebrews 1:5, 5:5, and Acts 13:33
Who hath ascended up into heaven, and descended? who hath held the wind in his hands? who hath bound up the waters together as in a garment? who hath raised up all the borders of the earth? what is his name, and what is the name of his son, if thou knowest?
I beheld therefore in the vision of the night, and lo, one like the son of man came with the clouds of heaven, and he came even to the Ancient of days: and they presented him before him.
1 Kings (Samuel) 10:6
1 Kings (Samuel) 10:10
1 Kings (Samuel) 11:6
1 Kings (Samuel) 16:13
1 Kings (Samuel) 16:14
1 Kings (Samuel) 19:20
1 Kings (Samuel) 19:23
2 Kings (Samuel) 23:2
3 Kings (1 Kings) 18:12
3 Kings (1 Kings) 22:24
4 Kings (2 Kings) 2:16
1 Paralipomenom (Chronicles) 12:18
2 Paralipomenom (Chronicles) 15:1
2 Paralipomenom (Chronicles) 18:23
2 Paralipomenom (Chronicles) 20:14
2 Paralipomenom (Chronicles) 24:20
2 Esdras (Nehemiah) 9:20
2 Esdras (Nehemiah) 9:30
Psalms 50:13 (51:11)
Psalms 103:30 (104:30)
The Trinity, Flemish School, c. 1500
The Holy Trinity, Lucas Carnach the Elder, c. 1515-1520
Eastern “Orthodoxy” Exposed: Their Heretical Doctrine Of God
Catholicism vs. An Eastern “Orthodox” View On The Divine Essence
Jesus’ own words: “I and the Father are one.” John 10:30
Corroborated by the testimonies of the Apostles who indeed recognized Him as God:
The testimony of St. John the Baptist:
Psalms 105:33 (106:33)
Psalms 138:7 (139:7)
Psalms 142:10 (143:10)
Aggeus (Haggai) 2:5