Thomas is one of the few Apostles to get his own feast day, but that is probably because we know so much about him compared to other Apostles.
Jesus seems to pick people who are able to be bold to the point of putting their foot in their mouth. Peter, Simon, James, Thomas; all good men and good friends but ones who put themselves out there - asking questions, making statements, trying to second-guess Jesus and his message.
We love them, not just because they loved the Lord and he them but because we can easily identify with their zeal and their ignorance. When they think as men think then they fail but the light bulb always seems to come on and they begin to see what it means to think like God.
Jesus does not shame them, but challenges them, gently (mostly) chiding them to come around to God's way of thinking.
And when they do, great things happen. Let us ask Thomas to help us "who have not seen" to proclaim "My Lord and my God!"
Thomas, called Didymus, one of the Twelve, was not with them when Jesus came. So the other disciples said to 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 into the nailmarks and put my hand into his side, I will not believe.” Now a week later his disciples were again inside and Thomas was with them. Jesus came, although the doors were locked, and stood in their midst and said, “Peace be with you.” Then he said to Thomas, “Put your finger here and see my hands, and bring your hand and put it into my side, and do not be unbelieving, but believe.” Thomas answered and said to him, “My Lord and my God!” Jesus said to him, “Have you come to believe because you have seen me? Blessed are those who have not seen and have believed.
-- John 20:24-30