D&C 103

Recently, many of the leaders of wards and stakes (ward & stake councils) as well as any interested saints were invited to a session of the training of new mission presidents and their spouses.  The topic was centered around the work of salvation and our individual responsibilities concerning such.  Having heard this instruction, I was touched by the word of the Lord concerning the saints that they are -

"...set to be a light unto the world, and to be the saviors of men;
10 And inasmuch as they are not the saviors of men, they are as salt that has lost its savor, and is thenceforth good for nothing but to be cast out and trodden under foot of men."  (Doctrine and Covenants | Section 103:9 - 10)

In my mind, being a savior would be doing that which others may not necessarily accomplish on their own.  Missionary work and preaching the gospel would fall under that definition in my mind.  If we are faithful in this and every commandment the Lord has given us, the Lord informs us -

"...verily I say unto you, that I have decreed a decree which my people shall realize, inasmuch as they hearken from this very hour unto the counsel which I, the Lord their God, shall give unto them.
6 Behold they shall, for I have decreed it, begin to prevail against mine enemies from this very hour.
7 And by hearkening to observe all the words which I, the Lord their God, shall speak unto them, they shall never cease to prevail until the kingdoms of the world are subdued under my feet, and the earth is given unto the saints, to possess it forever and ever.
8 But inasmuch as they keep not my commandments, and hearken not to observe all my words, the kingdoms of the world shall prevail against them."  (Doctrine and Covenants | Section 103:5 - 8)

I note that the conditions set for this promise and warning is based upon following His counsel and "all the words" He gives us.