The way Jesus deals with Thomas should give us all hope. This man who walked with Jesus, who in John 11:16 called the disciples to go die with Jesus, now refuses to believe the resurrection until he sees Jesus for himself. It's easy for us to look down on him, think of him as being maybe one step above Judas. But that not how Jesus saw him. Thomas asked for proof, and Jesus gave it to him. The end of the chapter gives a pretty solid reason for that: we have this gospel so that we can believe in Jesus. That is what Jesus wanted most for Thomas, and what he wants for us.