The Oil of Catechumens is the oil used in some traditional Christian churches during baptism; it is believed to strengthen the one being baptized to turn away from evil, temptation and sin.
The catechumen, the person prepared for baptism, is also anointed as a symbol of being the heir of the Kingdom of God, as kings and queens were anointed at coronations, and empowered for their Christian life as prophets were anointed for their ministry.
The Oil of Catechumens is intended to help strengthen the person about to be baptized, and prepare them for the struggle (ascesis) of the Christian life, the way a wrestler in ancient Greece and Rome was anointed before a wrestling match.
In the Eastern Orthodox Church, the oil of catechumens is blessed by the priest during the baptismal rite. After the consecration of the baptismal water, a vessel of pure olive oil is brought to the priest by the deacon. The priest breathes on the oil three times and blesses it thrice, and says the prayer of blessing.
The priest then pours a portion of the oil into the baptismal font, making the Sign of the Cross with the oil three times, as all sing Alleluia. The priest gathers some of the oil floating on the surface of the water onto the first two fingers of his right hand and anoints the catechumen, making the Sign of the Cross on the brow, breast, between the shoulders, on the ears, hands and feet. The catechumen is then immediately baptized.
During the baptismal rite, the priest says the following words as he anoints with the oil in the shape of a cross, "We anoint you with the oil of salvation in the name of Christ our Savior; may he strengthen you with his power, who lives and reigns for ever and ever."