The practice of baptism began long before the time of Christ. People of the Old Testament, as well as those of pagan religions, practiced baptism (immersion in water) to symbolize death of the old life and conversion to a new way of life. Jesus himself was baptized by John in the Jordan River to show that he was the “Lamb of God who takes upon himself the sins of the world.” In baptism are we united to the Body of Christ, the Church. In baptism, we die to sin and rise again in Christ.
Whenever possible, Orthodox baptism involves total immersion and is always performed in the name of the Trinity – Father, Son, and Holy Spirit. Christians coming from non-Orthodox backgrounds who have been baptized in the name of the Trinity generally are not re-baptized, but rather are chrismated and confirmed into the Faith.
Chrismation refers to the seal of the Holy Spirit. Chrismation takes place immediately after baptism, so even though it is technically a separate sacrament, baptism and chrismation are typically contained in the same ceremony. The major exception is in the confirmation of a previously baptized Christian, as stated above. The holy chrism, or oil, is drawn on the individual in the sign of the cross on forehead, ears, back, chest, hands, and feet.
Immediately after baptism and chrismation, the “newly enlightened” – infants as well as adults – receive Holy Communion.
Read about Holy Water and its use here.