The doctrine of the Trinity is simply that there is one eternal being of God - indivisible, infinite. This one being of God is shared by three co-equal, co-eternal persons, the Father, the Son, and the Spirit.

1. Now the catholic faith is that we worship
2. One God in Trinity and Trinity in Unity,
3. neither confounding the Persons nor dividing the substance.
4. For there is one Person of the Father, another of the Son, another of the Holy Spirit.
5. But the Godhead of the Father, of the Son, and of the Holy Spirit, is One, the Glory equal, the Majesty coeternal.
6. Such as the Father is, such is the Son, and such is the Holy Spirit;
7. the Father uncreated, the Son uncreated, and the Holy Spirit uncreated;
8. the father infinite, the Son infinite, and the Holy Spirit infinite;
9. the Father eternal, the Son eternal, and the Holy Spirit eternal.
10. And yet not three eternals but one eternal,
11. as also not three infinites, nor three uncreated, but one uncreated, and one infinite.
12. So, likewise, the Father is almighty, the Son almighty, and the Holy Spirit almighty;
13. and yet not three almighties but one almighty.
14. So the Father is God, the Son God, and the Holy Spirit God;
15. and yet not three Gods but one God.
16. So the Father is Lord, the Son Lord, and the Holy Spirit Lord;
17. and yet not three Lords but one Lord.
18. For like as we are compelled by Christian truth to acknowledge every Person by Himself to be both God and Lord;
19. so are we forbidden by the catholic religion to say, there be three Gods or three Lords.
20. The Father is made of none, neither created nor begotten.
21. The Son is of the Father alone, not made nor created but begotten.
22. The Holy Spirit is of the Father and the Son, not made nor created nor begotten but proceeding.
23. So there is one Father not three Fathers, one Son not three Sons, and one Holy Spirit not three Holy Spirits.
24. And in this Trinity there is nothing before or after, nothing greater or less,
25. but the whole three Persons are coeternal together and coequal.
26. So that in all things, as is aforesaid, the Trinity in Unity and the Unity in Trinity is to be worshipped.
27. He therefore who wills to be in a state of salvation, let him think thus of the Trinity.³

1. There is one God. True.
   
2. God is one person. False. See, for instance, statement 4 in the Athanasian creed.
   
3. God is one being. True. See James White’s definition of the Trinity.
   
4. There are three persons in the Godhead. True.  Statement 4, Athanasian creed.
   
5. The three persons in the Godhead are related eternally as Father, Son and Holy Spirit.  True. Statement 5, John Frame’s five assertions.
   
6. Each of the three persons of the Godhead is one-third of God. False. Each person is fully God; the Trinity is indivisible.
   
7. The Father is fully God. True.
   
8. The Father has the whole fullness of God’s being in himself. True.
   
9. The Father is eternal. True.
   
10. The Father is not the Son. True. The persons are distinct and not confounded.
    
11. The Father is not the Holy Spirit. True.
    
12. The Son is fully God. True.
    
13. The Son has the whole fullness if God’s being in himself. True.
    
14. The Son came into being at the time of the incarnation.  False. The Son is eternal and uncreated according to statements 7 and 9 of the Athanasian Creed. And of course, we have the scriptural statements that say that Christ was the agent of  the creation of everything as proof that he existed eternally. He is not a created being, but the Creator.
    
15. The Son was brought into being in eternity past. False, see directly above. That Christ was created by the Father before the rest of  creation is one of the doctrines of Arianism, a heresy denounced by both the Council of Nicea and the Council of Constantanople, but which nonetheless still exists today, for instance, in the teaching of the Jehovah’s witnesses.
    
16. The Son is eternal. True.
    
17. The Son is not the Father. True.
    
18. The Son is not the Holy Spirit. True.
    
19. The Holy Spirit is fully God. True.
    
20. The Holy Spirit has the whole fullness of God’s being in himself. True.
    
21. The Holy Spirit is eternal. True.
    
22. The Holy Spirit is not the Father. True.
    
23. The Holy Spirit is not the Son. True.
    
24. The persons of the Trinity are distinct. True.
    
25. In their nature, the Son and the Holy Spirit are co-equal and co-eternal with the Father.  True. See especially statement  26 of the Athansian Creed, although other statements pertain as well.     
    
26. The Son and the Spirit are subordinate to the Father in their essence or nature. False. In essence and nature they are all equal—equal majesty and glory; all three uncreated, eternal, infinite, etc. This false statement is one affirming a form of subordinationism, a heresy rejected by the early church.
    
27. The Trinity is unique. True.
    
28. There is both unity and diversity in the being of God. True.
    
29. The persons of the Trinity have distinct primary roles. True. This is hinted at in statements 20-23 of the Athanasian Creed and supported in scripture. Although all three persons are involved in all of God’s work, there are distinctions in their focus. We might summarize their roles like this: the Father plans, the Son accomplishes, the Spirit applies.
    
30. The Father, Son and Holy Spirit are simply different names for the one person of God showing himself to us in three distinct roles. False.  Since the Trinity consist of three persons (not one) who exist co-eternally, God cannot be just one person manifesting himself in different roles. Melanie gives a scriptural argument that this statement is false in the comments of the quiz. This false statement is a modalistic one, and modalism (or Sabellianism) is a heresy that has always been condemned within Christianity, but one that also continues to exist. The United Pentecostal Church (Jesus-onlyism), for example, affirms a form of modalism.
    
31. A right understanding of the Trinity is vital to right worship of God. True. Right worship is worship done for right reasons. An accurate view of God as Trinity is the foundation upon which we can worship each of the three persons in the Godhead. We know that only God himself is to be worshipped, right? So since the Son is fully God, co-equal and co-eternal with the Father, we have justification for worshipping him; but if he were not fully God, and a created being subordinate to the Father, we would not have justification for worshipping him.
    
32. A right understanding of the Trinity is vital to a right understanding of redemption. True. For one thing, in order for the Father to pour out his wrath on his Son and for the Father to accept Christ’s sacrifice on our behalf, the persons must be distinct. That the Son is infinite God also explains how his death can infinitely valuable and thus able to pay the just penalty of eternity in hell for all those he redeems.
    
33. Any analogy used to explain the Trinity will not represent it completely accurately. True, as we ought to expect, since the Trinity is unique. Nothing else is like it, so there is no good analogy for it. Most analogies used to explain the Trinity do a better job explaining a heretical view of God than the orthodox Trinitarian one. And do we really need analogies, anyway? God is incomprehensible; the Trinity is incomprehensible. While there are many true things we can know about it, I’d think we should be satisfied to live with a great deal of mystery in regards to it. In fact, one could argue that the errors in regards to God in Trinity have come from attempts to make the incomprehensible into something simpler to understand.
    
34. The doctrine of the Trinity cannot be derived from the Biblical text. False. The word “Trinity” is not in scripture, but the doctrine of the trinity comes directly from all the statements made about God and the persons of the Godhead in scripture.