I heard a story years ago which, I hope, will bring a lot of comfort to those who are taunted with the "if you had more faith..." issue. I was listening to a lady who called a radio pastor. The pastor was a wise, grandfatherly gentleman who has that calm reassuring voice that can melt all fear.
The lady, who was obviously crying, said, "Pastor, I was born blind, and I've been blind all my life. I don't mind being blind but I have some well meaning friends who tell me that if I had more faith I could be healed."
The pastor asked her, "Tell me, do you carry one of those white canes?"
"Yes I do," she replied.
"Then the next time someone says that hit, them over the head with the cane," He said. "Then tell them 'If you had more faith that wouldn't hurt!'"