And thus, with the sword and by bloodshed the inhabitants of the earth shall mourn; and with famine, and plague, and earthquake, and the thunder of heaven, and the fierce and vivid lightning also, shall the inhabitants of the earth be made to feel the wrath, and indignation, and chastening hand of an Almighty God, until the consumption decreed hath made a full end of all nations; (D&C 87: 6)
I want to write about the part of this prophecy that is in bold, for my understanding is that there will be two ways in which it will be fulfilled.
Fulfillment #1: the sword as military power, or just plain war
This means that people will be warring with each other using all manner of modern weapons: guns, bombs, missiles, torpedoes, nuclear, electromagnetic, chemical, biological, etc.
Due to the technology that advances at an ever faster rate, many of those who interpret last days prophecy (the Christians), as well as those who believe that interpretation (the Mormons) assume that the great last days destructions will be man-destroying-man, with his own man-made weaponry (in particular, the nuclear kind).
This interpretation is understandable where there is an ignorance of plasma science, cosmology and mythology. However, with plasma theology in mind, the great last days destructions can be correctly interpreted as the power of God, and not of man, destroying man, through interplanetary plasma discharges.
This leaves one to wonder, what part does the military power of man (his advanced technology) play in last days prophecy? The answer is: no part whatsoever. The follow-up question, then, is what happens to his technology?
Fulfillment #2: the sword as a literal sword
At some point in the future, all society, all nations, will be plunged into anarchy and all the advanced and advancing technology which we now have will come to an abrupt halt. There will be no more companies making ammunition or any of the multitude of military supplies we currently have. (The military industrial complex makes weapons to make money, selling them to governments. No governments, means no one to sell them to. This will be one of the many reasons why these plants will close up.) Ammo will quickly run out, leaving guns useless. Additionally, the conditions of the earth, planets and Sun, as well among men, will change so completely that all advanced weaponry will no longer be usable. Nevertheless, men will still be at war with each other and will desire to have weapons for defense and offense.
The manufacture of the relatively low tech weapon of choice of virtually all civilizations from the time of Adam to now, namely, the sword, will commence among all people. From then on out, and up to the time of the appearance of the Lord, men will use real swords (as well as other low tech weapons, such as the spear, bow and arrow, knife, etc.) to fight their battles.
This means that all the survivalists of the world, and especially here in America, who are stocking up on guns and ammo, thinking this will get them through the day, have it only half right. It may get them through the first half the day, but the time comes when there will be no more ammo, and unless they have a sword, or the means to make a sword, and the know-how of using one, they may not get through the second half.
Isaiah’s (and Micah’s) prophecy literally fulfilled
When the Lord appears, these prophecies will quite literally be fulfilled, as all those left alive will be using swords, not guns:
And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more. (Isa. 2: 4; see also Micah 4: 3)
A plowshare is “The share of a plow, or the part that furrows in the earth.” A share is “The part of a plow which cuts the ground at the bottom of a furrow; a plowshare.” And to share means “to cut; shear, cleave; divide, to form by cutting.” (All definitions taken from the massive Webster’s New International Dictionary, published in 1913.)
So, we see that it is entirely natural and consistent that swords will be beaten into plowshares, whereas guns (and other types of modern weaponry) makes no sense. Most Christians (and Mormons) interpret the above Isaiah and Micah passages to be figurative, but my understanding is that these propheces will be literally fulfilled.