Now Thomas, called the Twin, one of the twelve, was not with them when Jesus came. The other disciples therefore said to him, "We have seen the Lord." So he said to them, "Unless I see in His hands the print of the nails, and put my finger into the print of the nails, and put my hand into His side, I will not believe." And after eight days His disciples were again inside, and Thomas with them. Jesus came, the doors being shut, and stood in the midst, and said, "Peace to you!" Then He said to Thomas, "Reach your finger here, and look at My hands; and reach your hand here, and put it into My side. Do not be unbelieving, but believing." John 20:24-27, NKJV.
What do we know about Thomas the disciple? Not much! Outside of John's Gospel the only mentions of him appear in the lists of the disciples. But John provides us with a handful of passages that give us a glimmer of this "man in the background."
We first meet him as an individual disciple in John 11:16. Jesus had decided to go to Bethany after He had heard about the death of Lazarus. Thomas' response is revealing: "Let us also go, that we may die with him" (RSV). That short quotation provides us with a small glimpse of the man. It lets us know that Thomas was both courageous and pessimistic. He didn't expect much good to come out of the journey, but he was willing to accompany Jesus on it anyway. Thus we see loyalty to Him as a third characteristic.
The only other place we find Thomas speaking before today's passage is in John 14:5. Jesus had just told the disciples that they should not let their hearts be troubled because He was going to prepare a place for them and would return. He closed His brief presentation of the Second Advent by saying "and you know the way where I am going." Thomas' response was, "Lord, we do not know where you are going; how can we know the way?" (verses 4, 5, RSV).
In effect, Thomas was implying that Jesus hadn't made things clear enough. He was a person willing to move forward, but he wanted sufficient information before doing so,
That is what we find in John 20. But there the picture deepens a bit. We find Thomas unwilling to believe in the word of others. What they were claiming seemed to be too good to be true. They might have gotten one another overly excited and created something out of a sheer longing for release from agony and pain. His pessimistic nature with its desire for full information again surfaced. But when he met the resurrected Jesus his faith also came to fullness.
Some of us are like the hesitant Thomas, while others are like the impetuous Peter. If we were all Peters the church might run before it had sufficient knowledge. But if we were all Thomases we might never get started. The church of Christ needs both types for proper balance.