He did not work many mighty deeds there because of their lack of faith.  Imagine yourself rafting down a river, enjoying the cool summer breeze and the peaceful scenery.   Then you run into a huge log.   As you try to maneuver around it, your raft flips over, and you fall into the water, getting your feet caught between some rocks.   You panic and start thrashing about, and your friend jumps in after you.   But he has a hard time releasing you...