Paidion,
You wrote:
Because the words are nominative, I think Thomas was beginning a sentence with "My Lord and my God..." but he was so overwhelmed with the resurrection of Jesus, that he didn't finish the sentence. He may have been going to say:
"My Lord and my God has raised you from the dead!"
Look at the context. It is clear that there is a back and forth between Jesus and Thomas:
John 20:27-28
New American Standard Bible
27. Then
He said to Thomas, “Place your finger here, and see My hands; and take your hand and put it into My side; and do not continue in disbelief, but be a believer.” 28.
Thomas answered and said to Him, “My Lord and my God!”
I have heard the "missing words" speculation before. The context rules that out.
You also wrote:
Does it not make sense that the nominative would function as a nominative in this verse as it does in all other verses in which it occurs?
If Thomas were addressing Jesus, why did John not write these words in the vocative? What would be his reason to use the nominative instead of the vocative in one place and one place only in all of his gospel? And why would this not have been done anywhere else in the entire New Testament?
You must have missed what I posted earlier:
Mark 15:34
New American Standard Bible
34. At the ninth hour Jesus cried out with a loud voice, “Eloi, Eloi, lema sabaktanei?” which is translated, “
My God (theos), My God (theos), why have You forsaken Me?”
Here Jesus addressed God in the nominative. By your own admission ' "God" in the nominative: θεος (Matt 15:4)' the spelling is nominative. And we have
ho Theos mou exactly the same as in John 20:28!