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 nail marks 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." (Jn20:24-29)
Thomas the apostle was also ready to believe. But his belief depended on physical experience. He wanted to verify for himself the reality before believing. The verification by the others and their experience was in no way a proof for Thomas. For Thomas the experience had to be personal and physical and of his own expectation (unless I put my hand into the marks made by the nails).
Jesus, in this story, spoke of a belief that was based on inexperience and impersonal experience. This could be a belief that was based on the experience of the others. The other disciples told Thomas that they have seen the Lord. It was a first hand information. Thomas was not ready even for that. Jesus was speaking of a belief that was based on totally impersonal experience.
All of us long for a n experience of God in the religion. And any religion is valued in as much as it is able to give God experience. Can this experience be personal for everyone? Jesus does not seem to agree with this. What Jesus wanted his followers to belief was that Jesus was risen from the dead be it with experience e or without it.