JST - Matthew 24

As we read the words of the Savior on the Mount of Olives, we begin to understand the difference between references of the "world" and the "earth".  As pertaining to the world, the Savior -

"...as he sat upon the Mount of Olives, the disciples came unto him privately, saying: Tell us when shall these things be which thou hast said concerning the destruction of the temple, and the Jews; and what is the sign of thy coming, and of the end of the world, or the destruction of the wicked, which is the end of the world?"  (Pearl of Great Price | JS-Matthew 1:4)

The apostles understood that the destruction of the wicked would be the end of the world.  We know that this destruction will take place with His second coming as He ushers in the Millennium.  Reference to the world then would be concerning life on this planet, but more in line with the self-proclaimed "god of this world" even Satan.  Thus when the world is referenced, it is the in reference to the carnal, self-gratifying nature of those on the earth.

But in answer to their questions, the Savior would later respond -

"...thus cometh the end of the wicked, according to the prophecy of Moses, saying: They shall be cut off from among the people; but the end of the earth is not yet, but by and by."  (Pearl of Great Price | JS-Matthew 1:55)

Reference to the earth then is more in reference to the entity and eternal nature of the planet earth.  Brigham Young taught -

“When the Savior has completed the work, when the faithful Saints have preached the Gospel to the last of the spirits who have lived here and who are designed to come to this earth; when the thousand years of rest shall come and thousands and thousands of Temples shall be built, and the servants and handmaids of the Lord shall have entered therein and officiated for themselves, and for their dead friends back to the days of Adam; when the last of the spirits in prison who will receive the Gospel has received it; when the Savior comes and receives his ready bride, and all who can be are saved in the various kingdoms of God—celestial, terrestrial and telestial, according to their several capacities and opportunities; when sin and iniquity are driven from the earth, and the spirits that now float in this atmosphere are driven into the place prepared for them; and when the earth is sanctified from the effects of the fall, and baptized, cleansed, and purified by fire, and returns to its paradisiacal state, and has become like a sea of glass, a urim and thummim; when all this is done, and the Savior has presented the earth to his Father, and it is placed in the cluster of the celestial kingdoms, and the Son and all his faithful brethren and sisters have received the welcome plaudit—'Enter ye into the joy of your Lord,’ and the Savior is crowned, then and not till then, will the Saints receive their everlasting inheritances” (Journal of Discourses, Vol. 17, p. 117)