D&C 82

As the Lord mentions that the land of Kirtland is designated for a stake of Zion, He follows -

"For Zion must increase in beauty, and in holiness; her borders must be enlarged; her stakes must be strengthened; yea, verily I say unto you, Zion must arise and put on her beautiful garments."  (Doctrine and Covenants | Section 82:14)

I believe that "Zion" in this case is in reference to the Church.  And specifically, "her stakes must be strengthened".  I my mind, strengthening a stake would include greater righteousness, rescuing the less-active, and gathering Israel including the conversion of the elect (missionary work).