There is one question (at least one) that I have never had answered from the anti-Trinitarians. Most don't even try. It comes from one of the clearest expressions of the Deity of Christ as well as His "difference" with God -- John 1.
1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 He was in the beginning with God. 3 All things were made through Him, and without Him was not any thing made that was made (John 1:1-3).First, the easy stuff. What can we see without doing any real work?
We can see that "the Word" is an enigma. This "Word" is both God and with God. This Word, then, has both the same nature as God and yet a distinction from God.
We can see that this Word is the Creator. This is really problematic to those who claim that Jesus was a created being, because John goes out of his way to say this as categorically as he can. "All things were made through Him." No, that's not sufficient. Let's see it another way. "Without Him was not any thing made." Yeah, that says it again in reverse. But wait ... there's more. One might think that "any thing" refers to "any thing but him, of course." But John is equally clear as to what "any thing" refers: "Any thing that was made." Well, let's see ... what was made? That would be all Creation. That would exclude God. Anything but God was "made." So if "the Word" made everything that was made (which would include everything except God), then "the Word" cannot be a created being, else He would have made Himself -- an absolute impossibility.
So the "sticky" question ... who is "the Word"? Well, John doesn't leave us in the dark about that, either.
And the Word became flesh and dwelt among us, and we have seen His glory, glory as of the only Son from the Father, full of grace and truth (John 1:14).That leaves little room for guessing. "The Word" is "the only Son from the Father," who, as John goes on to explain, is Jesus.
Putting it together, we have Jesus (prior to becoming flesh) who is both the same nature as God and yet distinct from God who is also the Creator of all that exists. (If you still trip over "But ... God exists", perhaps it's a good time to review.) This seems to be an insurmountable question to me. To the modalist -- those who hold that God has operated in different modes, starting as YHWH and now as Jesus (including the "Jesus Only" crowd) -- you have a problem. John presents a distinction between God and the Word. To the Arians -- those who hold that Jesus was a created being -- and the Socinians -- those who teach that Jesus was a deified man -- you have a problem. John presents Him as the Creator of all things that were created. How did He make Himself? To the monophysite -- those that hold that Jesus only had one nature ... a divine one -- you have a problem. John clearly states that He became flesh. To the tritheist -- those who hold that there are three distinct gods (Yes, there are those who actually argue that.) -- you have a problem. John clearly says that Jesus was God -- a unity.
Now, admittedly this passage does not address the third person of the Trinity, but I have yet to have a valid answer from an anti-Trinitarian that explains this passage. The worst, the ones that don't even try, are the ones that claim that Jesus was a created being. How is it even remotely possible that this created being created Himself?
So the next time you hear "The Trinity is not found or taught in the Bible," keep in mind this passage and try to figure out for yourself how it is possible that such a claim could stand on its own for long.