Thomas had heard the report of the Eleven. And, true to his form of thinking, he did not accept the news without conditions.
Unless I see the nail marks in His hands, and put my finger where the nails have been, and put my hand into His side, I will never believe.
John 20:25
Thomas's words are often cited as an example of unbelief. But there is a fairer way to read them. Thomas is asking for the same evidence the other ten had already received. When Jesus appeared to the Eleven the first night, He showed them His hands and His side. Thomas is asking for the same treatment.
Eight days later, Jesus appeared again in the same upper room. This time Thomas was present.
And Jesus, without waiting for Thomas to say anything, addressed him directly:
Put your finger here and look at My hands. Reach out your hand and put it into My side. Stop doubting and believe.
John 20:27
The text leaves unsaid whether Thomas ever reached out to touch Him. It records only his response:
My Lord and my God!
John 20:28
That is the highest Christological confession in John's Gospel. Spoken by the most skeptical disciple, before the still-visible wounds of the Risen One.
Jesus answered with a phrase that points directly at the future readers of the Gospel:
Because you have seen Me, you have believed; blessed are those who have not seen and yet have believed.
John 20:29