Christianity is based on the Bible and Sacred Tradition. Studying these two sources we find the olive tree and olive oil to possess an essential position. Starting very early in the book “Genesis” Noah after the grounding of the ark on Mount Ararat let free a dove which returned having in its beak an “olive leaf” (Gen.8, 11). The olive branch according to Noah meant the end of the misfortune; it was a message of joy and peace. A symbol we meet till today. The oil for centuries offered the sweet light to sacred places such as the tent of testimony with the seven-branched lamp. The image of the “fruitful olive tree” occurs several times in the pages of the Bible.
Priests, kings as well as the prophets in order to be the chosen of God were anointed with oil. Sacred utensils were also rubbed with oil so as to consecrate them. Olive oil is also used in the Sacrament of Baptism: a principal component of the Sacred Chrism is the oil which is mixed with aromatic substances, blessed, and with the Sacred Chrism the newly-baptized is anointed and the altars of churches are inaugurated.
Within the tradition, we find the believers using for blessing or cure the so called “apomyroma” which is cotton with oil that we get from vigil lights of the Saints.
Also that which dominates in the Sacrament of Holy Unction, as the word indicates, is the oil that is blessed and then with it believers are anointed.
Nobody of course forgets that Jesus Christ after the Last Supper retires at the Mount of Olives and in particular in the Garden of Gesthemane, which in Hebrew means mill, a favorite place of meditation and prayer for Him. There, not only is he arrested, after Judah having pointed him out, but also His period of martyrdom begins.