The automobile was evidence that Henry Ford believed in his concept.
Who can count the number of concepts men said they believed - but never realized? They merely appeased themselves with stirred-up passions about fascinating ideas.
Jesus had and achieved an awesome concept. He empowered ordinary men and women to cast out demons, and to lay hands on the sick and they will recover.
Many today talk excitedly about God's power in us to heal the sick and make prisoners free. But really, until we're showing it, let's not say we believe it.
Perhaps it's still just a grand notion - a good idea.