the second Seal

  Revelation 6:3-4

(3) When He opened the second seal, I heard the second living creature saying, "Come and see." (4) Another horse, fiery red, went out. And it was granted to the one who sat on it to take peace from the earth, and that people should kill one another; and there was given to him a great sword.
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The second horseman is perhaps the most easily identifiable of the famed Four Horsemen of the Apocalypse, since both of its symbols, the fiery red color and the great sword, are well known to represent war. However, underlying this facile identification of the symbols are a few interesting details that add depth to them.
The Greek word John uses for "red" is purros or pyrros, meaning "the color of fire" (compare our words "pyre," "pyromania," "pyrosis"). This is not the normal Greek word for red (eruthros), but a more specialized term that suggests fieriness or flickering reds, oranges, and yellows like a flame. It is the same word that John uses to describe the redness of the Dragon (Satan) in Revelation 12:3 (the third and only other occurrence is in a proper name, Sopatros Purrou, which is strangely not fully translated in Acts 20:4). This particular color intimates heat and ferocity like an out-of-control wildfire.
The Hebrew language does not have a similar, biblical term. However, the color red or scarlet in the Old Testament frequently symbolizes blood, whether the blood of sacrifice (Leviticus 14:4, 6, 49-52; see Hebrews 9:19) or the blood of violence (II Kings 3:22-23; Isaiah 63:2-3; Nahum 2:3; etc.). Scarlet has two other interesting meanings: that of wealth and luxury (II Samuel 1:24; Proverbs 31:21; Lamentations 4:5; etc.; see Matthew 27:28; Revelation 17:4; 18:12, 16) and of sin (Isaiah 1:18; see Revelation 17:3). One could make a case that all these meanings could apply to the second seal.
The horseman's "great sword" is a translation of máchaira megálee. Again, this is not the ordinary sword of war (romfaia) but a short sword or long knife like a dagger. Frequently, máchaira is the knife used to prepare a sacrifice or to slaughter an animal for food. It is also the sword worn by magistrates and executioners. That the red horseman's sword is "great" (megálee) means either that it is larger or longer than usual or that it is highly effective in doing its job. Surprisingly, romfaia appears in Revelation 6:8: "And power was given to [the four horsemen] to kill with sword, with hunger, with death. . . ." A "great sword," then, is the equivalent of a thoroughly effective instrument of death.
The sword is often a symbol of God's judgment. David writes in Psalm 7:12, "If [the wicked] does not turn back, He [God] will sharpen His sword." In Isaiah 34:6, 8, in the context of the Day of the Lord, God combines the sword of judgment with the idea of sacrifice and slaughter:

The sword of the LORD is filled with blood, it is made overflowing with fatness, and with the blood of lambs and goats, with the fat of the kidneys of rams. For the LORD has a sacrifice in Bozrah, and a great slaughter in the land of Edom. . . . For it is the day of the LORD'S vengeance, the year of recompense for the cause of Zion.