Gerald Borchert’s commentary on John’s Gospel provides an excellent discussion of Thomas’ confession upon seeing the resurrected Jesus (John 20:28):
Thomas’s response forms the high point of confession in the Gospel. What it does is bring the Gospel full circle from the Prologue, where it is emphatically said that the “Word was God” (John 1:1) to this confession, “My Lord and my God.”
In the process of writing this Gospel the evangelist has proclaimed that Jesus was active in creation (John 1:2), the Word who became incarnate/enfleshed (John 1:14), the sin-bearing Lamb of God (John 1:29, 36), the Messiah (John 1:41; 4:25-26), the Son of God (John 1:48), the King of Israel (John 1:48), the new Temple (John 2:19-21), a teacher sent from God (John 3:2), a new symbol of God’s power exhibited through Moses (John 3:14), the evidence of the love of God (John 3:16), the Savior of the World (John 4:42), equal with God (John 5:18), the authority in judgment (John 5:27), the agent of God (John 5:30), the fulfillment of Scripture (John 5:39), the expected prophet (John 6:14), the “I am” (John 6:35, etc.), the supplier of living water (John 7:38), the one who was from God (John 9:31-33), the Son of Man (John 9:35), the consecrated/Holy one (John 10:36), the lifted up one (John 4:14; 12:32-34), the glorified one (John 13:31), the preparer of his followers’ destiny (John 14:2), the nonabandoning one (John 14:18), the one in whom we must abide and who is the basis for the fruitfulness of his followers (John 15:5-7), the sender of the Paraclete (John 15:26), the bearer of truth (John 18:37), the crucified King (John 19:15), the risen Lord (John 20:20) and God (John 20:26).
Thomas is often remembered for his doubt. However, I think his theologically profound confession completely outshines all his pessimism. While we may not see the resurrected Jesus now (cf. 1 Peter 1:8-9), may we respond to the message of his witnesses and believe (John 20:30-31).
“Blessed are those who have not seen and yet have believed” (John 20:29).