This father says, "Lord, I believe. Help my unbelief." This may be the perfect prayer, certainly one I need to pray all the time. Then he stumbles as he asks, "If you are able. . . " Jesus objects to the question! He will NEVER have ability problems in response to my requests.
The disciples couldn't cast out this demon and asked why. Jesus told them, "It comes out by prayer." Yet, the text doesn't record Jesus praying as he cast it out. I wonder how many things I'm unable to do that I would have been able to do if I'd prayed?
As the disciples argued about who was the greatest, Jesus took a child and stood him up in the middle of them. Show and tell! Jesus thinks we should take sin seriously enough to cut off body parts to avoid it!