John 20:24-29

But Thomas (who was called the Twin), one of the twelve, was not with them when Jesus came. So the other disciples told him, “We have seen the Lord.” But he said to them, “Unless I see the mark of the nails in his hands, and put my finger in the mark of the nails and my hand in his side, I will not believe.” A week later his disciples were again in the house, and Thomas was with them. Although the doors were shut, Jesus came and stood among them and said, “Peace be with you.” Then he said to Thomas, “Put your finger here and see my hands. Reach out your hand and put it in my side. Do not doubt but believe.” Thomas answered him, “My Lord and my God!” Jesus said to him, “Have you believed because you have seen me? Blessed are those who have not seen and yet have come to believe.”

We call Thomas the patron saint of strugglers in faith. He believed enough to look for Jesus, but not yet enough to believe in him. He struggled on his own, and found faith again in the community of the believers. He was an honest doubter. We can identify with him in our struggles of faith, and be called as he was to find the Lord in the community of his people.

Further commentary available here