Meta. On the road from Jericho (the external consciousness, or realm of reflected thought) up to Jerusalem (spiritual consciousness) there are dangerous places through which we have to pass. The thieves and robbers that we have to meet are thoughts of error that would turn us aside from the real Truth and would dissipate the life substance of mind and body in outer ways. "The thief cometh not, but that he may steal, and kill, and destroy: I came that they may have life, and may have it abundantly" (John 10:10). The greatest robber with which the race has to deal is the lie of the serpent: "Ye shall not surely die." This turns millions aside from the true seeking after life through the one source and giver of life--the indwelling Christ --to a multitude of error religious ideas, which exalt death as the way to heaven and to spiritual realization. This leads people to the grave and away from life eternal. We can find the life eternal only by a daily resurrection into life here and now, and not by letting go of the consciousness of life--which each one does who dies. The pure, unadulterated Christ Truth alone leads to life.
Adummim symbolizes the place in man's consciousness where the foregoing error thought is most likely to enter. This thought, if properly met, makes "the ascent of Adummim" the place, or state, of going up to life; but to those who fall into the hands of the robbers that infest the way (error, limited thoughts regarding life), it becomes a red place--a place of returning to sense consciousness and its results: death and the grave.