How many of the 44,000 differing Christian denominations take on the trinity? It is a lot, and given that it is a lot, one would think that God would have made sure that He would have explained, and made instruction for followers to accept this theory.....But no, there are as many arguments for as there are against as to the authenticate of this mind boggling, attempted to explaination by clergy, theory that cannot be shown to have any status in Biblical reference. On the contrary, the Bible is full of the one God status in so far as the almighty Creator of all things is concerned.
There is only one situation where God, the Almighty Jehovah would be denigrated to a lesser position and that one situation is Satan, his oppressor, the originator of the lie who would have people believe anything other than Jehovah being the Alpha and the Omega.
Satan is a god, money is a god to some, in many forms of 'Christianity' gods in the way of plaster saints are prayed to on a daily basis and given god status, so it is not so strange that so many people, blinded but the god of darkness, will stuff around with the trinity and not look to the many other falsehoods of Christendom.
Start with the one fact that there is only one truth, and work from there.
And, Old Mate, I know enough from your statement "The evidence for the trinity is very compelling and it is Biblical.", that IMO you have never studied the Bible,
But that is your opinion, your option, your right of choice, and I do not deny you your right of choice, just as you cannot deny me the right of my choice.