Many, many UR folks are trinitarian, myself included, but unfortunately not many of them are at these boards.
Some people, perhaps even some people around here would balk at the term trinitarian and assert that it's not a Biblical term to be found within the Scriptures, but neither is Unitarian and UR. All of these perspectives are labels based upon each person's or each Church's understanding of what the overall sense of the Scriptures is presenting. Catholics and Calvinists would still find me heretical 'cause I don't buy into the definitions of trinitarian by their theologians about 3 eternal coequals in the one Godhead. Scripture's clear about the subordination of the Son to the Father and the subordination of Holy Spirit to the Son. But I still regard the 3 in one as 3 yet one and most emphatically one, yet my personal relationship with each is unique.
Some people feel as though they have Scriptural reasons for not being trinitarian and some of it will come down to an argument over which of the ancient manuscripts of the Bible is the most reliable, the most ancient, and then it'll involve a lot of semantics on both sides of the conversation. Some people discount the idea of the trinity because they personally have zero relationship with Holy Spirit, although things may genuinely, sincerely, and emphatically be amazing between them and Father and between them and the Son.
They're somewhat acquainted with Father and Son, but haven't met Holy Spirit yet that Jesus indicated was someone just like Himself, yet distinct from Himself, and someone that would pass along what He was hearing from Father and Son. Holy Spirit is very distinct to me from Father and Son based both upon my understanding of Scripture and my intimate acquaintance and developing relationship with each. Hard to explain on the boards without speaking face to face where I could demonstrate what I'm talking about.
Another point where people likely get confused on the difference between the Son and the Spirit is not rightly dividing Christ Jesus's King and High Priestly activities from the operations and manifestations of Holy Spirit that are clearly distinguished in Scripture. So, people think we're exclusively talking about the Spirit of Son or Spirit of Father without a shade of distinction because the Scriptures do say that we've received them as well. There's zero distinction in the New Testament between believers and Christ Jesus Himself, in several important covenantal practical senses, yet that none of us are Christ Jesus Himself is glaringly obvious to all but the most in need of medications. And yet, when any of us steps into the Shoes and does everything and says everything in the Name of Jesus, we're not out of place 'cause the Scriptures say to do that. To me, the benefits of believing in trinitarianism outweigh the benefits of unitarianism 'cause of the illustration in Scripture and in being in relationship with each of them of the kind of oneness that we should ultimately have together as believers with God and with each other and the kind of oneness that married believers should have with one another.
Gary Amirault, the owner of the Tentmaker website, has requested that this particular topic be one of the ones that is NOT discussed at the boards because it's turned into really horrible arguments on the boards before. But if Paul (i.e. Pierac) is reading this later, I welcome his input and particularly some Scriptures that he's posted before when this has come up. I'm simply locking the thread per Gary's wishes, but if Pierac is a little long in seeing this thread, then you're welcome to PM him for an entirely different perspective from mine. I guess he'd regard himself as a Biblical Unitarian, not to be confused with the UUA that's 98% pagan. I likewise base my belief on the Scriptures, but I don't have a prepared list because it's never a subject that I feel needs defending and I don't think that if anybody in the history of the world has ever gone to Hell that it was ever over the trinity/unitarian debate. God's more concerned with your understanding the GodHeart, through Christ Jesus, than the GodHead. Besides myself, the moderator AbbasChild would probably still regard himself as a trinitarian, though he's seldom at the boards these days 'cause of a lot going on in his life right now. But you can try sending him a PM about it if you'd like, through the link at the top of the boards. I'm just honestly not sure how long it would be before you'd get a reply.
To me, it's not a matter that effects one's "eternity." Salvation is based upon belief that Christ Jesus is the only access to the Father, that His Blood alone wipes away our sin, and that God raised Him from the dead, according to the Gospel of John, Romans, and Colossians. It's repentance and faith towards God, according to Acts 17, Acts 20, and numerous other Scriptures. Even as important as the eventual Bodily return of Jesus Christ is, per Acts chapter 1, there's not a single verse that'll state that to not hold a certain position about how/when He comes back is in any dangers regarding their soul, their peace with God, and God's view of them through Christ's finished work. Trinitarianism/Unitarianism and probably a million other subjects are in the same boat. Great to research the Scriptures about and once you're aware of them you'll probably always have an opinion about them, even if you'd regard it as something you're treading softly about 'cause of not being 100% sure for whatever reason, but God's not broiling you like a potato in the oven over any stage you happen to be in regarding that.
As important as I personally believe that the virgin birth of Jesus Christ is because of implications regarding it that I see all over the Bible, including "why" the Blood of Christ is so important beyond the simple Covenant making aspect, I'm having a fallout with absolutely nobody over one passage in Isaiah and one passage in Matthew that mentions the virgin birth. I personally just try to emphasize what the Bible really emphasizes. One clear statement in the New Testament about the virgin birth in Matthew, possibly it being inferred in Luke without a direct statement to that effect that I'm aware of, and over 20 times that the New Testament will make a very firm statement about the Blood of Christ being what remits our sin. One or two, [possibly a third] passages about the virgin birth verses 21+ New Testament passages of Scripture that indicate that when they started opening up His skin, veins, and arteries that our sin was forever gone with the passing wind from that moment. Guess which one I'm going to spend more time emphasizing! While not believing that there's an amiss detail in the New Testament, I do believe that it's perfect in emphasizing what it emphasizes and that that should be a lesson for us for all time regarding what to spend the most time on. Now, when I'm in the presence of company that believes about the same as I do regarding that, then I may possibly get animated about the subject. But that's in a way where people are built up rather than torn down, know what I mean? That's when I'll get into Matthew 28:19, 2Corinthians 13:14, and three to five dozen other verses about it.
And again, you didn't do anything wrong. I'm locking the thread because the owner of the website doesn't want us going there 'cause in the past it's turned into the biggest mud wrestling whatever that you've ever seen on multiple occasions.