Gethsemane comes from two words in the Hebrew language. GATH, "a press," also "bitterness," & SHEMAN, "oil," (understanding and wisdom). Wisdom is always born of pain, that is, until the disciple has attained the high consciousness where pain has no power over him. The "diamond body" of the Adept is impermeable to pain and suffering and it is indestructible. Nothing can come in the way of the "diamond body." Christ Jesus inhabited such a body when he went to Gethsemane and the Way of the Cross. This was for the sole purpose of showing to mankind the Way of Wisdom.
Gethsemane is a place of personal sorrow, but becomes a place of sorrowing for the grief of the world. In the Garden of Gethsemane, its plants are watered by Christ's tears that are shed for the suffering of humanity, and for the helpless pain of the large amount of living creatures who cannot speak with a human voice. When one goes forward on the way towards high spiritual attainment, he becomes increasingly responsive to the sufferings of all living things around him. He feels every shooting pain as if it was his own hurt, and stores it deep within his heart.
The supreme lesson of Gethsemane is to learn to stand alone and say, "Not my will but, Thine be done." Many times we must follow Christ Jesus upon that lonely Mount, and drink of that cup, until the lesson has been learned. The disciple asks of one privilege, which is of sacrificing himself upon the altar of humanity, expecting no favors, no gratitude and no understanding. He desires only to live for service. This is an extremely high ideal, but it is one which all must accept as life's goal before they are fitted to attain ultimate liberation from Gethsemane. (http://rosiecrosse.tripod.com/chbwb3.htm - Bible: Wonder Book of the Ages).
In relation to the novel, Demian by Herman Hesse, "Jesus in the Garden of Gethsemane" is obviously a biblical allusion. This allusion is found on page 133 of the novel, and in context this allusion is comparing Emil Sinclair to Jesus.