I'm just curious how you anti-Trinitarians make sense of this verse then since clearly Thomas was speaking to the one human being, Jesus.
A well-known form of anti-Trinitarianism is Unitarianism. By the mid-20th century, American Unitarianism had developed into more of a philosophical and social (as in social issues and activism) position than a theological one. Indeed, it has become the case that a Unitarian is more likely than not to be an atheist. Many Unitarians were leery of merging with the Universalists in 1961, since to them Universalism smacked of superstition, so just try to imagine how they felt a couple decades later when neo-Pagans also joined the fold. Among Unitarian-Universalists (AKA "UUs"), the general attitude and approach is to gain wisdom from many sources, to learn and appreciate the teachings of great religious teachers such as Jesus (indeed, reading through the New Testament a few times more than a decade after I had become an atheist and two decades before joining a UU church, I found an appreciation for the teachings of Jesus and a strong suspicion of Paul's teachings about the Christ), and a tendency to allow for the use of the term "God" to mean whatever the speaker wants it to mean (from a Unitarian hymn: "Some call it evolution, some call it God"). To UUs, the Bible is the culmination of the religious tradition and wisdom of a couple peoples, but there's nothing magic about it.
And yet, it appears, there are also anti-Trinitarians who do, like Trinitarians, believe in the Bible as being magic.
There are different kinds of anti-Trinitarians (just as there is more than one stripe of Trinitarian). My advice to you is to not confuse the different types of anti-Trinitarians.
If you were to try to convince of something by throwing the Bible at me all the time, you could try that until your arms fell off but it would never make any difference, since my opinion of the Bible is different from yours.
At the same time, if an anti-Trinitarian, whether Bible-believing or not, were to argue to you that the Bible supports a non-Trinitarian view, then of course referencing the Bible,
including what the original says, would be very apt. As would your own arguments that the Bible does indeed support Trinitarianism.
Not that I'm criticizing your approach -- indeed, if I had the time, I would have been sitting here with popcorn enjoying the show -- , but rather I'm pointing out that there's a lot more to anti-Trinitarians than you may think.
On the flip side, I think that anti-Trinitarians here should pony up and be up-front about their position here. I think that Alter2Ego has been particularly dodgy about his position.