Hi Unconvinced!
It is up to the person to use the word Trinity or not, when i started out, I had no belief in God whatsoever and to me He was fake as Donald Duck and Santa Claus and I would try and argue with all the Christians who made an attempt to show me who this God was.
They said to me that all it takes is just one prayer and that prayer can require just about as no faith at all, but taking the step in doing so would make a world of a difference.
So one night i said to myself"What the hey" I'm bored, lets see what this person who calls Himself God will answer me or not?
And I said"God if your out there I can't see you, and if Jesus is real I can't see him either, neither is there any factual evidence that proves His ultimate existence in "HISTORY"
I prayed what Christians call the prayer of salvation kind of laughing when I did so. And from that time on to now and it has been over 20 years since that prayer has been prayed, and now my eyes are opened and now I can see God and no without a shadow of a doubt but with absolute certainty that He exists just as you and I exists but to a Greater degree.
So i'll leave you with this because I felt the same exact way you did regarding evidence and factual proof in History about the life of Jesus. Why is the historical evidence of Jesus somewhat clouded in mystery, where is the proof in history that he actually existed?
Where is the historical proof of Moses and the ten commandments?
Where is the proof of Jesus being crucified on a cross to die for the sins of all the world, to those that call upon him?
One of the most amazing gifts of all time is to see and know God without a shred of evidence and that is called "FAITH"
AND Jesus said unto those who have seen him, that Faith and those who have genuine faith are considered blessed forevermore!
God Bless!