Learn from Moronihah: Protect the Center of the Land

We can learn much from Moronihah's costly blunder, described in Helaman 1:26:

 26 For behold, Moronihah had supposed that the Lamanites durst not come into the center of the land, but that they would attack the cities round about in the borders as they had hitherto done; therefore Moronihah had caused that their strong armies should maintain those parts round about by the borders.

A few lessons:

1. Satan knows where our weaknesses are and is unafraid to hit us there. And by unafraid I mean he is eager to and inevitably will hit us there. If we are super fortified in the area of the Word of Wisdom but weaker in the Law of Chastity, for example, then Satan's efforts will focus more around inappropriate thoughts than around trying an illegal drug. 
2. We must remain vigilant to avoid being taken by surprise temptations. The Savior taught, "Behold, verily, verily, I say unto you, ye must watch and pray always lest ye enter into temptation; for Satan desireth to have you, that he may sift you as wheat." 3 Nephi 18:18
3. Every effort should be made to have the companionship of the Holy Ghost and be able to receive inspiration. It's hard to imagine this sort of breach happening to Moronihah's father, Moroni, because he was an inspired leader and always one step ahead of the Lamanites.
4. At the time that the Lamanites successfully took Zarahemla in the heart of the land, the Nephites were experiencing internal struggles, largely due to the secret acts of wickedness committed by Kiskumen and his cohorts. They had just murdered the chief judge and were mingling with the population. This wickedness in the heart of the land was a big factor in the Nephite's unpreparedness for the Lamanite attack.
5. No matter how well we appear prepared on the outside because we attend church, fulfill callings, serve others, etc, if our hearts are not sincere, our faith is not strong, and our conversion is not deep, then we are vulnerable to similar attacks. One interesting lesson from the Armor of God analogy found in the scriptures is that the Shield of Faith can be used as a mobile defense to protect any weak or vulnerable area of the body from oncoming attack.