Most of the time, falling means a lowering in spiritual state, from one closer to the Lord to one further. But, as with other common verbs, the meaning of "fall" is highly dependent on context in regular language, and in the spiritual sense as well. People fall on their faces in prayer, fall in battle, fall on others to attack them and fall on each other's necks in greeting. Stars fall from the sky, mountains fall on people, cities fall, and even faces fall. There's a lot of falling, in very different circumstances. When people fall on their faces in prayer -- it shows humility, and an acknowledgement of their own low state and need for the Lord's help. When they fall on each other's necks, it means a communication between the two spiritual states. At the other end of the scale, it illustrates complete spiritual destruction in the fall of a city.