Catholicism 101 Series: The Blessed Trinity

For awhile I have been thinking of starting a series of posts in which I write on the basic beliefs of Catholicism and evangelizing to people of other faiths and nonbelievers. My Catholicism 101 Basics of Catholicism will cover but will not be limited to : the Sacraments, Tradition, Saints, the Trinity, Papal infallibility, Incarnation, Mary, the Mass, Popes, encyclicals, heresies, misconceptions about faith and science being at odds, the development of Doctrine, moral teachings, as well as other issues, controversies, and topics in relation to the Church. I will be posting this on both Teresamerica and Tu Ne Cede Malis Contra Audentior Ito.


Catholics believe in the Trinity - God as Father, Son, and Holy Spirit. God is three persons which is the Triune God, or God is three persons in one God, or one God in three persons. Here is a portion of the Athanasian Creed which will help to explain the Trinity:

Whosoever will be saved, before all things it is necessary that he hold the Catholic Faith. Which Faith except everyone do keep whole and undefiled, without doubt he shall perish everlastingly. And the Catholic Faith is this, that we worship one God in Trinity and Trinity in Unity. Neither confounding the Persons, nor dividing the Substance. For there is one Person of the Father, another of the Son, and another of the Holy Ghost. But the Godhead of the Father, of the Son and of the Holy Ghost is all One, the Glory Equal, the Majesty Co-Eternal. Such as the Father is, such is the Son, and such is the Holy Ghost. The Father Uncreate, the Son Uncreate, and the Holy Ghost Uncreate. The Father Incomprehensible, the Son Incomprehensible, and the Holy Ghost Incomprehensible. The Father Eternal, the Son Eternal, and the Holy Ghost Eternal and yet they are not Three Eternals but One Eternal. As also there are not Three Uncreated, nor Three Incomprehensibles, but One Uncreated, and One Uncomprehensible. So likewise the Father is Almighty, the Son Almighty, and the Holy Ghost Almighty. And yet they are not Three Almighties but One Almighty.

So the Father is God, the Son is God, and the Holy Ghost is God. And yet they are not Three Gods, but One God. So likewise the Father is Lord, the Son Lord, and the Holy Ghost Lord. And yet not Three Lords but One Lord. For, like as we are compelled by the Christian verity to acknowledge every Person by Himself to be God and Lord, so are we forbidden by the Catholic Religion to say, there be Three Gods or Three Lords. The Father is made of none, neither created, nor begotten. The Son is of the Father alone; not made, nor created, but begotten. The Holy Ghost is of the Father, and of the Son neither made, nor created, nor begotten, but proceeding.

So there is One Father, not Three Fathers; one Son, not Three Sons; One Holy Ghost, not Three Holy Ghosts. And in this Trinity none is afore or after Other, None is greater or less than Another, but the whole Three Persons are Co-eternal together, and Co-equal. So that in all things, as is aforesaid, the Unity in Trinity, and the Trinity in Unity, is to be worshipped. He therefore that will be saved, must thus think of the Trinity.

God is all-loving, omnipotent, and omniscient. God is agape. God is pure unselfish love.   Therefore, since God has always been unselfish love, there must always have been more than one self in God.


Biblical case for trinity doctrine


The Bible makes these truths clear -

- The unity of God - there is only one God, one Divine Being, uniquely and supremely possessing one absolute Divine Nature or substance. There are not two or three Gods.

- The full divinity of God the Father of Jesus Christ.

- The full divinity of Christ the eternally begotten Son of God.

- The distinction between the Father and the Son (they are not the same Person).

- The Son is eternally equal to the Father in nature.

- The Son is in submission and obedience to the Father in love (this statement of truth is not in conflict with the one just above it AT ALL!).

- The full divinity of the Holy Spirit.

- The Personhood of the Holy Spirit (The Holy Spirit is not a mere impersonal divine force).

- The distinction between the Holy Spirit and both the Father and the Son (The Holy Spirit is neither the Father nor the Son).


Proof texts --


- The unity of God is expressed very clearly in the opening of the ancient traditional Hebraic hymn, the Shema Y'Israel: "Hear, O Israel: the Lord our God is one Lord" - Deuteronomy 6:4



- The full divinity of God the Father: Matthew 3:16 - "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."

"There is one [hen] body and one [hen] Spirit, one [hen] hope, one [hen] Lord, one [hen] faith, one [hen] baptism, one [hen] God and Father of all who is over all and through all and in all." (Ephesians 4:4-6)


- The full divinity of Christ as the only Begotten Son of God the Father: "In the beginning was the Word, and the Word was with God, and the Word was God. The same was in the beginning with God. All things were made by him: and without him was made nothing that was made...And the Word was made flesh, and dwelt among us, (and we saw his glory, the glory as it were of the only begotten of the Father,) full of grace and truth... And of his fulness we all have received, and grace for grace. For the law was given by Moses; grace and truth came by Jesus Christ...the only begotten Son who is in the bosom of the Father...Behold the Lamb of God, behold him who taketh away the sin of the world...this is the Son of God." (John 1:1-3, 14,16-17, 29, 34)

"I and the Father are one.” (John 10:30)

John 8:58 “Very truly I tell you,” Jesus answered, “before Abraham was born, I am!” ["I Am" (Ex. 3:14)].


- The distinction between the Father and the Son: “The Lord [the Father] says to my Lord [the Son]: ‘Sit at my right hand until I make your enemies a footstool for your feet’” Psalm 110:1



After Jesus said this, he looked toward heaven and prayed:


“Father, the hour has come. Glorify your Son, that your Son may glorify you.  For you granted him authority over all people that he might give eternal life to all those you have given him.  Now this is eternal life: that they know you, the only true God, and Jesus Christ, whom you have sent.  I have brought you glory on earth by finishing the work you gave me to do. And now, Father, glorify me in your presence with the glory I had with you before the world began. John 17:1-5

- The Son is eternally equal to the Father: "Christ Jesus, Who, though he was in the form of God, did not regard equality with God something to be grasped. Rather, he emptied himself, taking the form of a slave, coming in human likeness." (Phillipians 2:5-7 - the Greek word translated here as "grasped" is ἁρπαγμός harpagmos. In the King James Bible, that part of the verse renders that word by declaring that our Lord "thought it not robbery to be equal with God". The Greek word refers to siezing, as in robbery, but it can also signify clutching, clasping, cleaving to - i.e, retaining with vigorous security that which is already in one's possession. The implication is that the Son of God, prior to the incarnation, already properly enjoyed "equality with God", the state of being "equal with God". This also affirms full divinity, for only God can be equal with God. Combine that with the fact that there is only one God, and you have an affirmation that the Father and the Son are one in Being or substance.

- The Son is in submission to the Father in love: John 6:38 - "because I came down from heaven not to do my own will but the will of the one who sent me."

"Don’t you believe that I am in the Father, and that the Father is in me? The words I say to you I do not speak on my own authority. Rather, it is the Father, living in me, who is doing his work." (John 14:10)

- The full divinity of the Holy Spirit: "Go therefore and make disciples of all the nations, baptizing them in the name of the Father and the Son and the Holy Spirit..." (Matthew 27:19)

2 Cor. 3:16-18, "but whenever a man turns to the Lord, the veil is taken away. Now the Lord is the Spirit; and where the Spirit of the Lord is, there is liberty. But we all, with unveiled face beholding as in a mirror the glory of the Lord, are being transformed into the same image from glory to glory, just as from the Lord, the Spirit."


- The Personhood of the Holy Spirit: "And I will ask the Father, and he shall give you another Paraclete, that he may abide with you for ever. The spirit of truth, whom the world cannot receive, because it seeth him not, nor knoweth him: but you shall know him; because he shall abide with you, and shall be in you." (John 14:16-17)

- The distinction between the Holy Spirit and both the Father and the Son: "But when the Paraclete cometh, whom I will send you from the Father, the Spirit of truth, who proceedeth from the Father, he shall give testimony of me." (John 15:26-27) "But I tell you the truth: it is expedient to you that I go: for if I go not, the Paraclete will not come to you; but if I go, I will send him to you." (John 16:7)