Fausset's Bible Dictionary

(1) (Joh_11:8; Joh_11:15-16) When Jesus, for Lazarus' sake, proposed to go into Judaea again the disciples remonstrated, "Master, the Jews of late have sought to stone Thee, and goest Thou there again?" On Jesus' reply that His day was not yet closed, and that He was going to awake Lazarus out of the death sleep, and that He was glad of his death "to the intent that they might believe," Thomas evinced his devoted love on the one hand, ready to follow Jesus unto death (compare Paul, Act_21:13), on the other hand ignoring, with characteristic slowness to believe, Jesus' plain statement as to His going to raise Lazarus. He can see no hope of escape; his natural despondency anticipates death as the certain issue of the journey, still in self devoting affection he will brave all.

(2) (Joh_14:4-6) cf6 "Where I go ye know, and the way ye know;" Thomas saith, "Lord, we know not where Thou goest (yet Jesus had answered Peter's question, Joh_13:36), 'Lord, where goest Thou?' and plainly told the disciples He was going to cf6 'His Father's house', Joh_14:2, ascending to where He had been before, Joh_6:62), and how can we know the way?" Thomas still cannot raise his mind to the unseen future home where Jesus is going, or realize the way as through Jesus.

(3) (Joh_20:20; Joh_20:24-29) Thomas with morbid brooding over doubts had absented himself from the disciples' assembly on the first Lord's day, when "He showed unto them His hands and His side"; so he missed the immediate blessing (compare Heb_10:25). The disciples did not stand aloof from Thomas though he had stood aloof from them; they told him, "we have seen the Lord." But he said with an unreasonable demand for sense evidence which is alien to the very idea of faith, and at the same time with language that marks the vivid impression which his Lord's body nailed on the cross had made on his mind, "except I shall see in His hands the print of the nails, and put my finger into the print of the nails, and thrust my hand into His side (one sense, seeing, is not enough; not even feeling also will satisfy him unless he feels with both hand and finger the spear mark as well as the nail marks) I will not and cannot believe" (oumee pisteusoo).

A week of gloom to Thomas elapsed, the retribution in kind for his obstinate unbelief. Though Jesus might have cast him off yet He would not break the bruised reed; He condescends to Thomas' culpable weakness. On the next Lord's day, Thomas, laying aside his morbid isolation, attended the weekly assembly of disciples; though the doors were shut Jesus came and stood in the midst with His wonted salutation, cf6 "Peace be unto you"; then saith He to Thomas, with grave yet tender reproof (showing that He knew all that had passed in Thomas's mind and all he had said to his fellow disciples), cf6 "reach here thy finger, and behold My hands, and reach here thy hand, and thrust it into My side; and be ("become", ginou) not faithless but believing". Thomas said unto Him, My Lord and my God!"

A refutation of Socinianism, because Thomas addresses these words to Jesus. The highest confession of faith in Jesus' Godhead thus far made; see Peter's (Joh_6:69; Mat_16:16). As this forms the close of John's Gospel, before the supplementary chapter (John 21) was added, this ending recurs to the doctrine alleged in the Gospel's beginning, "the Word was God." Like Mary Magdalene (Joh_20:13) Thomas appropriates Jesus to himself, "my Lord and, my God." From the overwhelming proofs before him of Jesus' humanity Thomas believes in His Divinity. The resurrection of the Son of man proved that He was the Son of God (Rom_1:4).

All Christ's appearances in the 40 days were preparations for the believing without seeing (1Pe_1:8). Jesus spoke for all our dispensation what He said to Thomas, "because thou hast seen Me thou hast believed; blessed are they that have not seen and yet have believed" (2Co_5:7). Thomas was permitted to doubt, that we might not doubt ("Ab eo dubitatum est, ne a nobis dubitaretur"; Augustine). God's word, not demonstration, is the true ground of faith. Thomas is named next to Peter among the seven on the sea of Galilee, a proof that he was a fisherman like Peter (Joh_21:2). He appears for the last time among the disciples met after the ascension (Act_1:13). The case of Thomas does not sanction but condemns skepticism, for if others were to demand the same tangible visible proofs as Thomas demanded miracles would have to be so continual as to cease to be miraculous, and sight would supersede faith. The unbelief of Thomas drew forth such an infallible proof of the identity between the crucified and the risen Lord that he who any longer disbelieves and is consequently condemned is left without excuse.

Taken from: Fausset's Bible Dictionary by Andrew Robert Fausset (1821-1910)