“Then saith he (Jesus) to Thomas, Reach hither thy finger, and behold my hands; and reach hither thy hand, and thrust [it] into my side: and be not faithless, but believing. And Thomas answered and said unto him, My Lord and my God.”
It is often claimed that since Thomas referred to Jesus as “my Lord, My God (John 20:28),” that Jesus was God. An ignorance of the context of the verse and of Christian doctrine prompts this claim. The context of the verse talks about an unbelieving Thomas being surprised when Jesus offers him evidence.
The exclamation, “My God,” on his part was just astonishment. We use such exclamations everyday while talking to people. This doesn’t mean that the person we are talking to is God. For example, I see John cutting his wrist with a Rambo knife. I say: “My God, John what are you doing?” Do I mean that John is God? Of course not.
Similar is the use of the expression by Thomas. If you go into Jewish or Muslim societies even today, you’ll hear people exclaim “My God, my Lord,” at every situation which surprises them or causes them anguish or is astonishing.
In the verse above Thomas says: “My God, my Lord.” He was not claiming that Jesus was his (1) God and (2) Lord. If he did then the church and the disciples should have stamped him as a heretic right there and then. Because claiming that Jesus is Lord and God is a violation of Christian doctrine, which asserts that there is One God, the Father and One Lord, Jesus. Jesus can’t be God and Lord. “…yet for us there is but one God, the Father…and one Lord, Jesus Christ …(I Corinthians 8:6)”. Believing the above (i.e Jesus is Lord and God) would leave a person with unorthodox doctrine branded by the church as Sabellianism, Patripassianism, Monarchianism.