From Mark Vernon:

So clearly there’s a pattern emerging. This is a sceptic and the gospel says it’s quite important that in the balance of personalities around Jesus there is somebody who asks the awkward questions who is not a kind of Pollyanna optimist and who eventually will only be convinced by the confrontation of a relationship. At the end of the day, in fact, he says ‘I need to touch the risen body.’ But when Jesus appears to him as a risen body, Thomas doesn’t touch. He says ‘now, I see enough.’