Eight days after Thomas' disavowal, Jesus appears again to the disciples when Thomas is around. He gently chides Thomas for his unbelief by inviting Him to touch His wounds on His hands and side. And He says, "Blessed are those who have not seen and yet have believed."
Jesus is not calling for a blind faith here. Blind faith is believing in something that is contrary to what is true or believing something without really knowing what it is one believes. This is not to say that faith is no different from knowledge. They are closely related but they are not the same. A valid faith is based on knowledge, not just on feelings or hopes. But faith by nature is outside the domain of knowledge. It is one thing to know our parents; it is another to actually trust our parents. Satan knows God, quite possibly better than any of us. But he doesn’t trust God. It is one thing to gain knowledge through scientific endeavors. But it is another to think that science is the only method of obtaining knowledge. That is called scientism, a belief system. And it is one thing to say that it's difficult to believe in the resurrection of Jesus Christ; it is another to say that we know Jesus didn't rise again from the dead.