Hello there, there seems to be no one here supporting the Blessed Trinity, so here I go. It's one of my first times here, so plese be patient as I make a few humble comments of things I've learned about the Trinity.
An argument I read about either on one of the many essays or posts I've read here is that the Trinity was invented to convert polytheistic-pagans. I won't go crazy quoting the Bible here but Genesis 3:22 says: "Then the Lord said,"see, the man has become like one of us, knowing good and evil..."" there's plenty more Scriptural examples supporting the existence of the Trinity even before the conversion of pagans to Christianity was at it's best. In the times of early Catholic colonies in the United States and Africa, the Church was against the practice of matching patron saints to African gods. This gave birth of the hybrid sect of voodoo which is farely recent compared to the doctrine of the Trinity. This argument might have come from the fact that Christians (as early as Paul) used philosophy and other pagan concepts to present the Gospel in a way they might understand it. The Gospel is universal, offered to everyone and can be preached in any linguistic or visual way as long as it does not trivialize or distort it.
For those of you who already know all about Christianity you can stop reading, but if you just don't like how the Trinity sounds and you're rejecting the doctrine because of ethnocentric reasons then give yourself a chance and keep reading.
In one divine nature there are three persons (Father, Son, and Holy Spirit). No one of these is the other, each is Himself. The Father is God, the Son is God, the Holy Spirit is God. They are not three Gods but one God. "Three persons in one nature." The only thing is that if one does not define person and nature, they drop out and all we are left is 3 in 1 with the impossible mathematical equation of 3=1.
Nature means there is a person, an "I" who posseses the nature. To be brief it is "my nature" not "my nature's me." If one is in a dark room and hears a noise, one would ask "what is that?" or if there's a person's shadow with undistinguished features one may ask "who is that?".
Person is that which distinguishes one from the other who have the same nature (and I know you get the point by now so I'll stop bolding). The nature of the trinity is God and it has three persons, if asked "who are you?" each could give His own answer, Father, Son, or Spirit. To the question "what are you?" all three could answer God. It is necessary to emphasize two points here:
1. The three persons do not share the divine nature, it can not be divided but possesed in its totality
2. The persons are distinct but not separate, each is Himself, each is what He is by possesing the one same nature. Apart from that nature no one of them could ever exist.
A quick example is: Family=nature, Person= Father, Mother, or Child if either one is separate or out of the equation they are cut off and therefor do not exist as a Father, Son or Mother (no need to mention the disintegration of the family unit in modern times).
Only at first does this seem dry and unrewarding. The rewards for persistance are inmense. The Trinity is a mystery, not a contradiction.
AD MAJOREM DEI GLORIA