In this chapter of war, we find the Nephites having so declined as a people, that their wickedness will now lead them to total destruction. Even so, they had some military success when they gathered together in cities that were strongholds. In cities where the Nephites weren't gathered, the Lamanites completely destroyed them.
Family is one way of gathering to protect ourselves. It is easier to destroy an individual than it is to destroy a group of mutually minded people. Can we make our family a stronghold? We can as much as we collectively allow ourselves to be led by our Shepherd (see v. 17).