Why is Jesus called Theos?
Did Thomas think he was addressing the Almighty Yahweh, standing before him the flesh? If Thomas was addressing Jesus as God Almighty, we should expect Jesus to have said something that would definitely clarify that he was the Almighty, but he doesn't. If Jesus was God Almighty in the flesh, he surely missed the opportunity to make such clear when Thomas made this expression. Instead, he simply answers: "Because you have seen me, you have believed. Blessed are those who have not seen, and have believed." (John 20:29) Jesus emphasizes Thomas' belief that Jesus was really alive (and thus the risen Christ, the Son of God), which he doubted, and yet he doesn't say anything about Thomas' statement concerning his expression "ho theos mou" -- "the god of me". What belief is it that Jesus considered important? John answers in verse 31: "but these are written, that you may believe that Jesus is the Christ, the Son of God, and that believing you may have life in his name." By calling Jesus the Christ, this would mean that Jesus was anointed, but by whom? The scriptures answer that he was anointed by Yahweh, his Father. (Isaiah 61:1; Psalm 45:7) By calling Jesus the "Son of God", this certainly does not say that he is Yahweh, who is his Father, but rather that he is the Son of Yahweh, his Father.
Let us start by referring to a earlier incident where the Jewish leaders accused Jesus of blasphemy because, being a man, he made himself "God". (John 10:33) The claim is false, and Jesus denied that he was God by stating over and over that he was sent by God, could do nothing of his own self, everything he had was given to him by God, etc. In the immediate response to the accusation made the Jewish leaders, Jesus responded: "Isn't it written in your law, 'I said, you are gods?' If he called them gods, to whom the word of God came (and the Scripture can't be broken), Do you say of him whom the Father sanctified and sent into the world, 'You blaspheme,' because I said, 'I am the Son of God?' " (John 10:34-36) Again, instead of claiming to God Almighty, Jesus very clearly clarified that he was sent by God, his Father, Yahweh, and that he was the Son of God -- not God Almighty Himself.
The question has been raised concerning the usage of the definite article ho before theos. It has been claimed by some that since the definite article is used that Thomas was definitely calling Jesus God Almighty. Those who argue this usually assume that the expression ho theos always means God Almighty. Actually, this is not true. The expression ho theos is used of Satan the Devil in 2 Corinthians 4:4. As mentioned earlier, the definite article is used because of the possessive nature of pronoun. See #13 "with possessive pronouns"
However, by comparing the verse earlier:
While scholars, including some trinitarian scholars, are divided over whether Thomas was referring to Jesus or his Father as "the God of me", if Thomas was actually calling Jesus his God here, then it must be in the sense that Moses, the judges, the angels, and the sons of God are called "gods" -- ones having special power, and not as God Almighty -- the only source of all power, for the context as well as the rest of the Bible indicates that Jesus is not God Almighty. -- Exodus 7:1; 21:6; 22:8,9,28 (compare Acts 23:5); Psalm 8:5 (compare Hebrews 2:9); 82:6,7 (see John 10:34-36); 86:6-8; 95:3; 50:1.
We will add there is nothing in John 20:28 about Jesus' being a person of God, nor is there anything about there being three persons in God. Thus, the trinitarian idea has to be read into what Thomas said.
Additionally, if John is actually referring to Jesus as his God in the same sense as Jesus refers to the Father as "my God" and "your God" in John 20:17, then this would make Jesus the Father. Of course, our trinitarian neighbors deny that Jesus is the Father, as do we; we simply show where this line of reasoning would lead. It should be noted that our Oneness friends do understand Jesus to be the Father. Again, this line of reasoning must be read into passage.