After the second seal is opened, the keeper of the north appears, Nergal-Mars, the horseman on the red horse with his great sword. As god of war, he takes peace from the earth, and he kills with his sword. The sword refers to the earlier Persian culture in which the exterior world of matter is conquered with the sword.
In the Sumerian-Babylonian culture red is the color of Nergal-Mars and the north. Among the four elements, water belongs to the north (Schult, p.116), as it embodies the passions of the soul and the red blood, in which feelings of sympathy and antipathy wave up and down.
The north is the direction of mid-night in which man sinks in the waters of sleep and dreams and enters the domain of the unconscious astral soul.
In the Seal epoch, the sword also represents the battle between what is part of the upward movement of human intelligence purified to wisdom and what has to go down as egoism in man’s blood. Dullaart (p. 52-53) sees in this horseman man which is fighting, encouraged by Lucifer, who is stirring up passion, jealousy and blind hate, resulting in violence, terror and war. Without overcoming this barrier no peace is possible.
The second horseman on the red horse also takes away the world power of peace, with the purpose of preventing man to neglect, as a result of lethargy, the care for the divine (Steiner, GA 8, p.121).