Easier to Retain than to Retake

Alma 59:9

"And now as Moroni had supposed that there should be men sent to the city of Nephihah, to the assistance of the people to maintain that city, and knowing that it was easier to keep the city from falling into the hands of the Lamanites than to retake it from them, he supposed that they would easily maintain that city."

Moroni knew that it is easier to retain something than to try and get it back. Sometimes it is impossible to get back. This principle can be applied to the Law of Chastity, the Word of Wisdom, and other commandments. It is much easier to obey the commandments then to break them and try to get better. When we start on a path of sin, we sort of change. It's hard to change back.