I believe the Trinity is the most efficacious way for God to work through us and in us.

I reason like this:  God is Our Father because He is the Creator of everything, the Father of all that exists. Why couldn't He be seen as a mother, then, the way some pagan peoples imagine the creator god? First, because a mother creates a baby out of her own substance. She and the baby are one until the baby is born. This is unlike the way that God created us. He created us out of a substance that is separate from Him:  matter. As science has shown, this matter, or atoms, is the same material that all of God's Creation is made out of. God, however, is not made out of atoms. In other words, we, and the rest of Creation, are not made out of the same stuff as God.

Secondly, think about the Incarnation. If God were a mother, how would He have been a parent to Jesus? Would a mortal human have served as the Father? The thought is quite revolting! We know that Jesus's conception was planned from the beginning of time, so God knew that Jesus would have to have an earthly mother and a Heavenly Father in order to unite the human and divine natures.

At the same time, in order to avoid God having to "mate" with Mary, as the pagans believed happened with their gods and humans, a third agent is needed. This agent must be equal to God and part of the Godhead but able to act without the Other Two having to appear to us. This agent is the Holy Spirit. Imagine if God were one single entity, as Muslims believe. This would mean that in the Incarnation, Mary would in a sense have been impregnated by her own son! Clearly this is also unacceptable!

So we see that three Persons are needed to complete God's work. Why not four or five or ninety-six? I suppose because of God's own economy. So many persons are not needed and in fact might be confusing for us to comprehend. After all, the poor Muslims, and a few Protestants, are confused with just three!

That's my own weak manner of understanding it, anyway. I'm sure some of our other members can contribute something if they're not too busy arguing about how many antipopes there really are.

Well, I don't have a Mass to go to right now.  Otherwise I'd love to sit and chat about fun things like the Trinity, to indulge in speculation.  But until I have a Mass to go to, I will continue blasting away at heresies -- or are they just errors? -- until some priest out there decides to step out of the pack and become Catholic.

Sorry, I couldn't resist the opportunity to take a quick jab. :rolleyes:

But you described it well, St. Jude.  I thought the Trinity is supposed to be a mystery, but you just did some de-mystifying.  I guess the mysterious element comes into play when, as a mortal, you try to envision one God in three Persons.  How does the Holy Ghost look in heaven, for instance?  And will God the Father and God the Son be separate in terms of physical space?  They must be, because Christ is at the right hand of the Father.  Yet they're the same Godhead.    

But to answer Spouse's question about the Trinity being necessary, yes and no.  God being all-powerful theoretically could have chosen another way.  He could have theoretically chosen another woman besides Mary to be His Mother as well.  Yet the Word was before time was.  In that sense, there could have been no other way, but you must understand that this isn't due to a limitation of God's power, but just because this was how He always knew He was going to do it.  Or that is my understanding at this point.

He could have chosen another way, but He didn't. Therefore the Trinity must have been the most perfect way, either for Him or for us; more likely for us, so that we could get a grip on it, I imagine.

Here's what I don't get -- in the Bible it speaks of the Word being "in the beginning."  But how could God have a beginning?  Isn't he eternal?

I think Genesis is referring to the beginning of Time and Creation, in other words, our beginning. It's another way for us to grasp it in our own feeble little minds.

I forgot to mention that I may have spoken in error in the first post when I said, "Imagine if God were one single entity..." Of course, God is one single being, or entity. I was trying to find a synonym for "Persons" in that sentence but I don't know if the Church has used some other word in its place. Any other word, such as "entities," "aspects," "manifestations," etc. would seem to open the door to heretical interpretations.

 We say that God is a necessary being. But I wonder if His being a Trinity is a necessity or not. Could God choose to be a dulaity or just one person if He wanted?
  I know the doctorine of Trinity of God and believe in it. I just wonder if The Second Person owes His being to God The Father who begget Him. Could God The father decide not to begget Him? Could God choose to be more than Three?

I think that it is kind of like asking if God could choose not to exist.  Since God is immutable, then, no, he could not choose to be not infinite, not omnipresent, not omniscient, not good, not loving, etc.  Since God has always existed and has no cause, He must have always been triune in nature.