[quote:1fz9hpw7]And my other question is…why? Why 3 persons?[/quote:1fz9hpw7]
Frank Sheed explained it this way (although we do not know why it is 3):

God is infinite in love and knowledge. The only being whom He can properly know and love infinitely is Himself. The knowledge of Himself is the Son. The Son and the Father must both be God because if one were not then God would not have infinite knowledge of Himself. The love between Father and Son is the Holy Spirit. Again, if the Holy Spirit were not also God then the love would not be infinite.

There is an apparent heirarchy in the Trinity based on the above (Father begetting Son; Holy Spirit proceeding from Father and Son); however, no member of the Trinity is above another. As we profess in the Athanasian Creed:

21. The Father is made of none, neither created nor begotten.

22. The Son is of the Father alone; not made nor created, but begotten.

23. The Holy Spirit is of the Father and of the Son; neither made, nor created, nor begotten, but proceeding.

24. So there is one Father, not three Fathers; one Son, not three Sons; one Holy Spirit, not three Holy Spirits.

25. And in this Trinity none is afore or after another; none is greater or less than another.

26. But the whole three persons are coeternal, and coequal.

27. So that in all things, as aforesaid, the Unity in Trinity and the Trinity in Unity is to be worshipped.