D&C 29

The Savior says that He -

"...will gather his people even as a hen gathereth her chickens under her wings, even as many as will hearken to my voice and humble themselves before me, and call upon me in mighty prayer."  (Doctrine and Covenants | Section 29:2)

Of this gathering -

"...they shall be gathered in unto one place upon the face of this land, to prepare their hearts and be prepared in all things against the day when tribulation and desolation are sent forth upon the wicked."  (Doctrine and Covenants | Section 29:8)

In my mind, this "one place" is -

"...the gathering together upon the land of Zion, and upon her stakes, may be for a defense, and for a refuge from the storm, and from wrath when it shall be poured out without mixture upon the whole earth."  (Doctrine and Covenants | Section 115:6)

Thus, one of the purpose and work of stakes is "to prepare their hearts and be prepared in all things against the day when tribulation and desolation are sent forth".