Then David ran, and stood over the Philistine, and took his sword, and drew it out of the sheath of it, and killed him, and cut off his head therewith. When the Philistines saw that their champion was dead, they fled.
In applying this story, I believe it is legitimate to see Goliath as representing the many enemies that frustrate individual believers as we seek to live for God. However, I believe primarily the application deals with defeating those enemies bent on defeating and destroying God’s people en masse. Contemporary movements designed to discredit God and remove Christianity from a land are what Goliath personifies.