Alma 52:9

"And he also sent orders unto him that he should fortify the land Bountiful, and secure the narrow pass which led into the land northward, lest the Lamanites should obtain that point and should have power to harass them on every side."

Though the pass was narrow and seemingly insignificant, loosing it would cause great calamity. By loosing that one small pass the Nephites would be exposed 'on every side.'  Giving up something small can lead to greater devastation. This can relate to sin.  Sometimes sinning a little doesn't seem bad, but it can desensitize us and give Satan access to us 'on every side.'